_______ astonishes us is that AlphaGo defeated the human champion.
A. Which B. When
C. That D. What
With the new family planning policy _______, many young parents are considering having their second child.
A. introduce B. introducing
C. to introduce D. introduced
The number of Hutongs in Beijing is decreasing, ______ they still attract tourists from all over
the world.
A. or B. and
C. but D. so
Since its start, WeChat ______into the most popular messaging communication service in China.
A. has developed B. developed
C. develops D. was developing
People around us ______ affect our thoughts and behaviors.
A. must B. can
C. should D. would
In the early days, Beijing Opera ______ on open-air stages or in teahouses.
A. performed B. was performed
C. performs D. is performed
