20 1 1 physics, chemistry, physics, do we have to do experiments? Or draw lots?

***8 I am a lottery player in Anhui 1 2 3 4 5 6 7 8.

Identification of Chemicals 1 Hydrogen Peroxide and Water

2 verify the law of conservation of mass

3 Prepare 10g 5% sodium hydroxide solution.

4 crude salt purification

Physics 1 measuring the density of metals.

2 car light bulb power supply

3 Find out the relationship between voltage and current

4 convex lens imaging law