sheep是可数名词吗?

题目

sheep是可数名词吗?
there`s___sheep under the tree.
A.a little B.little
C.a few D.few
请大侠帮我选择一下,

答案

A,因为前面是there is
是可数的,但是其复数形式和sheep一样.
例句：There are a lot of sheep.
sheep
[Fi:p]
n.
羊,绵羊,羞答答的人,胆小鬼,信徒
sheep
[Fi:p]
n.
sheep
羊,绵羊
a black sheep
败类；害群之马；不肖之徒
make sheep's eyes at sb.
愚笨地向某人献殷勤