_______he had failed many times, he didn’t give up and succeeded in the end.A. Unless B. Although C. If
I ____ my clothes when my father got home.
We should protect the earth because it's home to ____ animals.
The police told the boys ____ in the street .It was dangerous.
— What about going to the zoo by bus? — ____.
It is difficult ____ me ____ English well. But I’ll study harder.