10、 The time is not far away ________ modern communications will become widespread in China’s vast countryside.
A. as B. when
C. until D. before
11、________ is known to everybody, Taiwan is a part of China. We must unify it.
A. It B. As
C. Which D. What
12、 I shall never forget the day ________ Shen Zhou V was launched, ________ has a great effect on my life.
A. when, which B. that, which
C. which, that D. when, that
先行词是Taiwan is a part of China整个主句，一般由as或which引导定语从句，但which引导的定语从句只能放在主句之后，另外，as有“正如”之意，而which没有，所以用as。顺便说说，原句改为：It is known to everybody that Taiwan is…= What is known to everybody is that Taiwan is…
两空都是考查定语从句，先行词分别是the day和Shen Zhou V was launched, the day在定语从句中作状语，用when引导;后句是非限制性定语从句，不能用that，要用which。