Last term our maths teacher set so difficult an examination problem _____ none of us worked it out.
| A．that | B．as | C．so that | D．which |
178. This is the only article of those that ______ written by him.
| A．was | B．were | C．is | D．Were |
179. This is the best book ______ I have been looking for all this year.
| A．who | B．whom | C．which | D．/ |
180. Good advertisements may well _____ the consumers’ emotional needs as well as providing information.
| A．refer to | B．see to | C．turn | D．lead to |
182. An oil ship accidentally sank in the ______ off the coast, which caused _____ among the residents.
| A．water; panic | B．waters; panics | C．water; panics | D．waters; panic |
183. --- You look pale, what troubled you?
--- I ______ my dead friend.
| A．am thinking about | B．was thinking about | C．had thought about | D．will think about |