32. Tens of thousands of trees _____ in
问题:
32. Tens of thousands of trees _____ in the area in the past few years.
A.have been planted
B.were planted
C.have planted
D.had planted
32. Tens of thousands of trees _____ in the area in the past few years.
A.have been planted
B.were planted
C.have planted
D.had planted