问题
选择题
Make ______ a habit to put whole-grain biscuits, nuts or raisins in your backpack.
A．/
B．this
C．that
D．it
答案
答案：D
考查代词。句中用it作形式宾语，真正的宾语为不定式to put whole-grain biscuits, nuts or raisins in your backpack，选D。