问题
单项选择题
Roots have the ability to ______
A．make proteins
B．obtain fresh air
C．produce inorganic nitrogen
D．carry out activities without energy
答案
参考答案：A
解析：[分析] 细节题型。 见第一段第六句：Roots are capable of making their own proteins and other organic compounds．所以选项A是答案。