It is said that Chinese eat ______ vegetables per person today as they did about 30 years ago.

A．more than twice

B．as many as twice

C．twice as many as

D．more than twice as many

美国的国家临床实验室标准委员会（NCCLS）用于临床化学干扰实验的文件是（）

A.EP5－A

B.EP6－P2

C.EP7－P

D.EP9－A

E.EP10－A