----How unhappy your roommate looks!
----Yes，but he’s not willing to tell me what it is____ is troubling him.
A. what B. which C. as D. that
----How unhappy your roommate looks!
----Yes，but he’s not willing to tell me what it is____ is troubling him.
A. what B. which C. as D. that
D
该题考查特殊疑问词what引导的强调句作tell的宾语，当强调句中有特殊疑问词时应把疑问词放在句子前面。若将该句改为非强调句为: but he’s not willing to tell me what it is troubling him.