1.Only after a year ( ) to see the result of my experiment.A.I began B.I had begun C.have...
1.Only after a year ( ) to see the result of my experiment.
A.I began
B.I had begun
C.have I begun
D.did I begin
2.( ) in the fields for two hours,they took a rest.
A.Having worked
B.Working
C.Worked
D.Being worked
为什么
第一题c为什么不对