A. That B. It C. As D. What
【答案】C 固定用法as is known to all：眾所周知。本句的意思是：“眾所周知，吸煙過多會引起肺癌。B 用于it is known to all that…句型。
2.The investigation, ___ will soon be published, was made by John.
A. at which the results B. the results on which
C. whose results D. at whose results
【答案】C 此句考查非限制性定語從句。C選項正確,whose在從句中作定語;whose results=the results of which =the results of the investigation,定語從句修飾investigation;B選項中的on改成of就對了。
3. ______ is well-known, the environment in China is badly in need of improvement.
A. It B. That C. As D. What
【答案】C此題考查的是as 引導的特殊定語從句。As is well known/ as is known to all/ as we all know：眾所周知。
4. They overcame all the difficulties and fulfilled the plan ten days ahead of schedule, ____ was something we had not expected.
A. that B. this C. it D. which
【答案】D 逗號后為非限制性定語從句，只能由which 或者who 引導，不能用 that。
5. ____ is well known, light, like heat, is a form of energy.
A. It B. What C. Just as D. As
【答案】D句意為：“如我們所知，光跟熱能一樣是一種能量的形式。”as is well known 為非限定性定語從句，修飾整個主句，意為“如我們所知”;as 代表整個主句“光跟熱能一樣是一種能量的形式。”
6. The day breaks ________the birds are singing.
A. in that B. which C. on that D. in which
【答案】A 天亮了因為鳥兒在歌唱。in that 因為。
7. Liquids are like solids ______ they have a definite volume.
A. in that B. for that C. with that D. at that
【答案】A 液體像固體一樣有確定的體積。in that 因為。
8. Criticism and self-criticism is necessary _____ it helps us to find and correct our mistakes.
A. by that B. on that C. on that D. in that
【答案】D 批評和自我批評很重要因為他幫助我們找出和糾正我們的錯誤。in that 因為。
9. Britain’s press is unusual ________ it is divided into two very different types of newspaper：the quality press and the popular press.
A. in how B. in what C. in which D. in that
【答案】D 英國出版社不同于普通出版社，它被分為兩種不同種類的報紙，高質量的報紙和流行報紙。in that 因為。
10. The high income tax is harmful ______ it may discourage people from trying to earn more.
A. in that B. in which C. that D. which
【答案】A 高稅收有害，因為他可能會挫傷人們試圖掙更多錢的積極性。in that 因為。