问题补充:
Because he works far away from his parents, he visits them only.
A. independently
B. commonly
C. occasionally
D. frequently
答案:
A. independently
B. commonly
(答案→)C. occasionally
D. frequently
解析:考查副词:A. independently独立地B. commonly普遍地C. occasionally 偶尔地,D. frequently频繁地,句意:因为他工作的地方离父母很远,只能偶尔回去看看他们。选D。