1_cow is _useful animal.It can give us milk.A.the;a B.a;an C.the;an D.a;a

1_cow is _useful animal.It can give us milk.A.the;a B.a;an C.the;an D.a;a
1_cow is _useful animal.It can give us milk.A.the;a B.a;an C.the;an D.a;a

1_cow is _useful animal.It can give us milk.A.the;a B.a;an C.the;an D.a;a
A
首先第二空只能用a,因为它不是元音读音开头的
第一空用定冠词表示类指

选择A
奶牛是一种有用的动物。
useful 发音：['ju:sful] 所以并不是元非开头，所以前面只能用a,不能用an，排除BC.
这里的cow不是指一只奶牛，而是指奶牛这个种类，是特指，所以用the，排除D.
所以选择A