问题
单项选择题
You didn't have to write the essay if you didn't want to. It was()
A.compulsory
B.suitable
C.alternative
D.optional
答案
参考答案:D
You didn't have to write the essay if you didn't want to. It was()
A.compulsory
B.suitable
C.alternative
D.optional
参考答案:D