Question

1. a scientist conducted an experiment to determine how the amount of salt in a body of water affects the number of plants that can live in the water. in this experiment the independent variable is

a) the temperature of the water
b) the number of plants in the water
c) the water
d) the amount of salt in the water

Explanation:

在实验中，自变量（independent variable）是研究者主动操纵、改变的变量，因变量（dependent variable）是随着自变量的变化而变化的变量。本题中科学家研究盐的含量对水中植物数量的影响，盐的含量是自变量，植物数量是因变量。

Answer:

D. the amount of salt in the water