问题补充：
It has been five years since this party. Many people wonder whether it will stay on.
A. has come to power
B. came to power
C. has been in power
D. in power
答案：
A. has come to power
(答案→)B. came to power
C. has been in power
D. in power
解析：考察时态，根据句子结构可知，该处填的是谓语，因此排除D，it has been 时间段 since sb did sth,意为自从某人干某事有多少时间了，因此选择B
