Misunderstandings from lack of social communication，unless properly，may lead to serious problems．
| A．arisen；handling | B．arising；handled |
| C．rising；handled | D．risen； handling |
___ you lose the paper document, sign in www. Sina.com, __ you might download all you need.
| A．If, which | B．So long as, what | C．In case, where | D．Even if, as |
I have heard a lot of good things about you I came back from abroad.
| A．since | B．until | C．before | D．when |
He wrote a letter ______ he explains what had happened in the accident.
| A．what | B．which | C．where | D．how |
Do not let any failures discourage you, for you can never tell ________ close you may be to victory.
| A．how | B．that | C．which | D．where |
Microblog is a platform ________ people can express their thoughts and communicate with each other by sending posts.
| A．which | B．where | C．what | D．when |