uk milf stella paris strips and wanks at babestation

Welcome to the original primary and secondary education resources network!

Scientific knowledge contest for primary school students

Time: 2021-01-13 18:04:59 test questions I want to contribute

Scientific knowledge contest for primary school students

From primary school, junior high school, high school to university and even work, we are more or less exposed to the test questions, with which we can better assess the knowledge and talent of the reference. What kind of questions can help us effectively? The following is a small series of carefully arranged primary school students' scientific knowledge contest questions, for reference only, hoping to help you.

1. "Pure water", "space water", "distilled water" and other commodities as daily drinking water are not conducive to children's health due to the lack of some ingredients. Do you think that at least the trace substances needed to be added in the preparation of the above-mentioned commodity drinking water are: a

A. bicarbonate of calcium and magnesium B. salt containing iodate C. disinfectant D. sodium bicarbonate

2. At present, the amount of CO2 emitted into the air is increasing year by year, and the most worrying thing about this is: B

A. it will reduce the oxygen content in the air, which is not enough for human to breathe

B. it will increase the earth's temperature, melt glaciers and cause ecological imbalance

C. It will cause the human body to inhale a large amount of CO2 and damage the health D. it will cause a large amount of limestone to dissolve and destroy the natural scenery

3. The main chemicals that destroy the ozone layer are chlorofluorocarbons (CFCs). Scientists call on human beings to pay attention to the protection of the ozone layer. In the ozone layer, the beneficial effects of ozone on human beings are: D

A, absorb CO2 B, supplement O2 C, absorb infrared D, absorb ultraviolet ray

4. "White pollution" usually refers to C

A. white dust from smelter B. white dust from lime kiln C. plastic waste such as polyethylene. D. white construction waste

5. Green food refers to d

A. food with green color B. food containing chlorophyll

C. clean and hygienic food in processing and packaging

D. It is safe and pollution-free food in the production and processing of raw materials

6. The goal of green chemistry is: a

A. reduce environmental pollution B. design compounds that are beneficial to human health and make the environment safer

C. prevention in the bud, and eventually eliminate chemical pollution sources D. study and transform basic raw materials and starting compounds

6. The leavening agent for fried dough sticks contains an element which is very harmful to human body. It is (a)

A. aluminum; B. Copper; C. Iron; D. Lead.

7. Which of the following is the correct composition of baking powder (c)

A. nitric acid and sodium carbonate; B. Tartaric acid and copper carbonate; C. Citric acid and sodium carbonate; D. Citric acid and ammonium bicarbonate.

8. Which of the following is a carbonated beverage (b)

A. mineral water; B. Soda water; C. Liquor; D. Chrysanthemum tea.

9. The degree of beer refers to (d)

A. the number of grams of alcohol in 100g beer; B. The number of grams of maltose in 100 g wort;

C. the volume of alcohol in 100 volume beer; D. The number of grams of sugars in 100 g wort.

10. The metabolic process of alcohol in human body is (d)

A. alcohol acetic acid acetaldehyde carbon dioxide and water; B. Alcohol sugar carbon dioxide and water;

C. alcohol fat carbon dioxide and water; D. Alcohol acetaldehyde acetic acid carbon dioxide and water.

11. The product of liquor brewing with starch is (a)

A. starch maltose glucose alcohol; B. Starch glucose maltose alcohol;

C. starch sucrose glucose alcohol; D. Starch fructose glucose alcohol.

12. Check whether the driver drives after drinking. The substance is (b)

A. silica gel containing Fe2O3; B. Silica gel containing CrO3;

C. silica gel containing CuSO4; D. Silica gel containing Ca (OH) 2.

13. The longer the liquor is stored, the purer the aroma is. The reason is (a)

A. aldehydes decreased and esters increased; B. The number of esters decreased and aldehydes increased;

C. amino acids were formed in wine; D. Alcohol has an aroma.

14. Artificial fiber refers to (b)

A. fiber like polymer compounds synthesized by chemical reaction from natural small molecular organic compounds;

B. fibrous materials made by chemical processing from natural polymer compounds;

C. products produced by artificial spinning;

D. fibrous macromolecular compounds are synthesized by chemical reaction from artificially prepared materials.

15. Burning fiber, smelling the smell of burning paper, the fiber is (d)

A. silk or viscose fiber; B. Hemp or polyester; C. Silk or wool; D. Cotton or viscose.

16. The main ions in temporary hard water are (a)

ACaMgHCO; BCaMgSO4Cl-;

C HCO3SO4Cl-; D. Only Ca and Mg.

17. Sodium tripolyphosphate is contained in phosphate washing powder, which has adverse effects on the natural environment. The reason is (c)

A. It has strong toxicity and can destroy animals and plants; B. It has strong acidity and can acidify water body;

C. It is a kind of fertilizer, which can make aquatic plants multiply in large quantities and reduce the oxygen content in water;

D. It can cause sodium poisoning in animals in water.

18. Washing clothes with hard water should not use soap, because (b)

A. soap can react with substances in hard water to form toxic substances;

B. stearate, which can produce calcium and magnesium, is deposited on the surface of the fabric;

C. It can produce strong corrosive substances and corrode clothes;

D. It can produce odorous substances and pollute clothes.

19. The most commonly used method is (c)

A. blue litmus test paper; B. Starch potassium iodide test paper; C. PH test paper; D. Congo red test paper.

20. The reason is (d)

A. the toilet water contains a proper amount of essence; B. The toilet water is poisonous;

C. The flower water contains 70-75% phenol; D. The water contains 70-75% alcohol.

21. Mix the iodine wine with the red medicine solution (mercuric red), and the result (a)

A. the formation of a highly toxic substance mercury iodide; B. Mercury iodide, a non bactericidal substance, was produced;

C. formation of bromomercury red and precipitation of solid iodine; D. Mercury is formed.

22. The incorrect one of the following statements is (c)

A. the stronger the alcohol concentration, the stronger the ability of protein coagulation; B. Alcohol is often used for medical disinfection;

C, 70-75% alcohol can not only coagulate the protein, but also continue to penetrate into the bacteria.

D. alcohol can coagulate protein and kill bacteria, so the stronger the alcohol concentration, the stronger the bactericidal ability.

Related articles:

one Questions of science knowledge contest for primary school students in 2020

two Questions of knowledge contest for primary school students

three Examination questions of employment knowledge competition

four Questions of knowledge contest of Chinese traditional culture

five Questions of nursing knowledge competition

six Questions of knowledge contest in primary school

seven Questions of knowledge contest for female workers

eight Reading knowledge contest

nine Questions of environmental protection knowledge competition

daddy4k papa intelligent ne perd pas sa chance davoir des relations sexuelles avec ses fils nouvelle copine lustful old granny rides two cocks vrallure busty ebony beauty daizy cooper plays with her sex toys in virtual reality loan4k le banquier est pret a aider une fille si elle donne quelque chose en retour daddy4k sweetie and boyfriends old dad celebrate her birthday with sex