1.How long dose a jacket like this last me? _______________________ (这要看你多长时间穿一次).

2. The theory he advanced has proved _________________ (对许多传统概念的一种挑战).

3. The manager ___________________ (本可以亲自参加会议),but he was called away for some urgent business abroad.

4. Both research and practical experience have shown that a __________________ (均衡的饮食对健康是必不可少的).

5.They requested_________________(我借的书还回图书馆) by next Friday.

答案与解析:

1.It depends on how often you wear it。本题考察一个固定搭配：要看(取决于)：depend on：多久一次用how often表示。

2.(to be )a challenge to many traditional notions / concepts.证明是…：be proved to be;挑战：challenge

3.could have attended the meeting in person/by himself。对过去的假设could have done表示本来可以但是没有; “参加会议”的说法是attend the meeting/ conference;亲自：in person/ by oneself。

4.a balanced diet is essential to health.均衡饮食:balanced diet;对……必不可少：be essential to

5.that I(shuold) return the books borrowed to library /the books I borrowed (should) be returned to the library.他们要求我在下周五之前把借的书还回图书馆。request 有“要求”的意思时，引导的宾语从句要用虚拟语气，结构为：request that sb. (should) do sth.