【单选题】
A You plant 5 seeds each in a different type of soil,to see which soil is best for growing plants.
B You interview 10 farmers about their recommendations for the best way to grow plants.
C You collect samples of soil from 5 different farms to test which soil has the highest level of pollution
D You survey 100 farmers to ask them which types of plants they grow on their farms
查看更多
