I tried hard to get some information about the new technology out of his mouth but he rem

问题补充：

I tried hard to get some information about the new technology out of his mouth, but he remained．

A. quiet

B. secret

C. silent

D. calm

答案：

A. quiet

B. secret

(答案→)C. silent

D. calm

解析：本题为四个形容词的区别，quiet为“安静的”，secret为“秘密的”，silent 为“沉默的”，calm为“心情平静的”，故选C项。