排列下面的句子。

A. Danny is very happy.

B. He asks the waiter if the hotel has a computer.

C. Danny misses Steven very much.

D. Steven has a computer.

E. He wants to send an email to Steven.

F. Danny has a friend named Steven.

G. The waiter shows him where the computer is.

（）是利用微生物的发酵作用，将夏季青绿饲料有效保存的方法之一，是确保家畜常年均衡供应饲料的有效措施。