问题补充:
Beijing a lot over the years. Now it has become one of the biggest
in the world.
A. changes; cities
B. changed; city
C. has changed; cities
D. changed; cities
答案:
A. changes; cities
B. changed; city
(答案→)C. has changed; cities
D. changed; cities
解析:句意:这些年北京变化很多。现在它已经成为世界最大的城市之一。与时间短语over the years.连用时,用现在完成时。由one of来修饰时,后面用名词的复数形式。故选C。