问题补充：
The boss praised the young man for his hard work, though he experience.
A. was lack of
B. was lacking in
C. lacks of
D. was lacking of
答案：
A. was lack of
(答案→)B. was lacking in
C. lacks of
D. was lacking of
解析：be lacking in是习语，意为缺乏，其后通常接experience, frankness,
courage等抽象名词。选a是错误的，因为lack可用做名词和动词，但不用做形容词；选c是错误的，因为lack用做动词时，它是及物动词，其后不用介词(注：用做名词的
lack后可接介词of)；选d是错误的，因为没有be lacking of这个搭配。lack of＋名词： The plants died for lack of water.
