What are the two types of plants discussed in this week's lesson? Where do plants get the materials they use to make food?

From air and soil.

Explanation:

Plants takes materials from air such as carbondioxide gas which enters in the leaves through stomata whereas the water and nutrients such as nitrogen, phosphorus and potassium etc taken by plants from the soil with the help of roots. These materials combines with each other in the presence of light that produces food in the form of glucose and oxygen gas.

answer; basic psychology;

answer; the intervening variable;