So far we ( ) about 1000 trees. a.planted b.have planted c.have been planted d.to plant

题目

So far we ( ) about 1000 trees. a.planted b.have planted c.have been planted d.to plant
说明原因

答案

B
因为前缀so far是到目前为止的意思,表明已经种了1000棵树,所以用现在完成时,就可以排除AD剩下B C但C是have been后应加上v+ing.,所以就选B