It is such a modern machine few of the workers know how to operate.A. asB. whichC. thatD

问题补充：

It is such a modern machine few of the workers know how to operate.

A. as

B. which

C. that

D. the one

答案：

(答案→)A. as

B. which

C. that

D. the one

解析：such …as…引导的定语从句。as代替先行词machine在从居中充当operate的宾语。