问题补充：
At the age of eight, he a group of child dancers.
A. joined in
B. attended
C. took part in
D. joined
答案：
A. joined in
B. attended
C. took part in
(答案→)D. joined
解析：考查短语辨析。joined in 和took part in的宾语是活动，attended 的宾语是会议、讲座、婚礼等等。Joined 的宾语是组织或团体或某人。句意：在八岁的时候，他加入了儿童舞蹈团。所以选D。
