用户的电子邮件地址由两部分构成,中间使用 【16】 间隔。
参考答案:@
解析: 参见选择题第17题解析。
---Guess what! I have got the highest score in the final exam.
---- Great! You ______ worked very hard and put a lot of energy into it.
A.must
B.must have
C.should
D.should have
抽风机机壳一般用钢板制成()型,在结构上主要考虑()和()。