D．disappointed; disappointed

　　解析：选D　句意：他脸上失望的表情表明他很失望。用­ed形式的形容词修饰look, face, voice等，表示主语(人)感到怎么样也用­ed形式的形容词。所以答案为D。

　　4．The computer was used in teaching.As a result, not only ________， but students became more interested in the lessons.

　　A．saved was teachers' energy

　　B．was teachers' energy saved

　　C．teachers' energy was saved

　　D．was saved teachers' energy

　　解析：选B　在not only ...but also ...句型中，当not only置于第一个分句句首时，第一个分句要用部分倒装语序。又因为第一个分句为被动句，因此答案为B项。

　　5．The accident caused some ________ to my car, but it's nothing serious.

　　A．harm B．injury

　　C．ruin D．damage

　　解析：选D　句意：这场事故给我的车造成了一些损坏，但问题不严重。根据短语搭配cause some damage to ..."对......造成一些损坏"，选D项。harm"伤害，损害"，常用于do harm to短语中；injury"伤害"，常用于对人身体的伤害；ruin"毁灭"。

　　6．We all agreed to the plan he ________ at the meeting.

　　A．has put forward B．had put up

　　C．had put forward D．put out

　　解析：选C　从agreed判断后面的定语从句应使用过去完成时。put forward意为"提出，提议"，符合语境。

　　7．I had hardly got to the office ________ my wife phoned me to go back home at once.

　　A．when B．than

　　C．until D．after

　　解析：选A　句意：我刚到办公室，我妻子就打电话叫我立刻回家。had hardly done something when ...为常用固定句型。

　　8．He appears careless, but ________， he is a very careful person.

　　A．in all B．in reality

　　C．in return D．in a word

　　解析：选B　句意：他看起来很粗心，但事实上，他是一个非常细心的人。in reality意为"事实上"，相当于in fact。in all"总计"；in return"作为回报"；in a word"总之"。

　　9．What shall we use for power when all the oil in the world has ________？

A．given out B．put out