问题补充:
The young man in studying paid no attention to the outside world.
A. involved
B. involving
C. to be involved
D. being involved
答案:
A. involved
B. involving
C. to be involved
(答案→)D. being involved
解析:考查非谓语动词。be involved in全神贯注于。在句中作定语,相当于定语从句,who is involved in,who is 省略。句意:专注于学习的那个年轻人没有注意到外面发生了什么。