区别sometimes,sometime,some time ,some times

题目

区别sometimes,sometime,some time ,some times
1.Let's have dinner together ______ next book.
2.I ______ receive letters from him.
3.I will be away for ______.
4.He has been to Beijing ______.
5.I forgot seeing her ______ before.

答案

1 sometime(同5)
2 sometimes有时
3 some time一段时间
4 some times几次
5 sometime 不定的某个时间