问题 填空题

用适当的介词填空

①Plants react __________light.

②They reacted strongly ___________the unreasonable rule.

③Iron reacts_________ water and air to produce rust.

④Certain acids (酸)react_________ metals to lead to chemical changes

答案

①to    ②against    ③with     ④on/upon  

单项选择题 A1/A2型题
单项选择题