red is a symbol of warmth, it can sometimes make people feel uneasy or even frightened.
| A．As | B．While | C．If | D．Since |
_______a reply, he decided to write again.
| A．Not receiving | B．Receiving not | C．Not having received | D．Having received not |
There seemed nothing else to do but ______ a doctor.
| A．to send for | B．to call for | C．send for | D．to call in |
Hearing the _______ news, we all felt_______ .
| A．encouraging; encouraging | B．encouraged; encouraged |
| C．encouraged; encouraging | D．encouraging; encouraged |
_______the road, be careful.
| A．While crossing | B．When cross | C．Crossed | D．Being crossed |
_______twice, he didn't want to try again.
| A．Failed | B．Failing | C．Having failed | D．To fail |