酶分子中决定酶促反应特异性的部分是（）

A.酶蛋白

B.辅基或辅酶

C.金属离子

D.底物

E.催化基团

Which of the following dictionaries is a great contribution made by Hornby to EFL teaching（）

A．Longman Dictionary of Contemporary English.

B．he Concise Oxford Dictionary.

C．Everyman's English Pronouncing Dictionary.

D．The Advanced Learner's Dictionary of Current English.