Question

A lot of trees _________ on the hill yesterday．

1. A.
   are planted
2. B.
   will be planted
3. C.
   have been planted
4. D.
   were planted

Answer 1

D
考查被动语态的时态。选项中各句均为被动语态，因此不必考虑。句中的时间状语为yesterday，用一般过去时态。故选D。