—It is very important for young people to learn _____ useful foreign language.

—I know that, so I am working hard at English. [ ]

A. a

B. an

C. the

D. the

关于急性胰腺炎时淀粉酶的说法下列错误的是（）

A.重症胰腺炎的淀粉酶值可正常或低于正常

B.部分急腹症的淀粉酶一般不超过正常值的2倍

C.胆石症不会有血清淀粉酶的升高

D.尿淀粉酶值受患者尿量的影响

E.胰源性胸腔积液和腹水中的淀粉酶值亦明显升高