Chọn đáp án đúng, giải thích lý do. The climate of china is similar in many ways to.......( that of the USA / the USA/ which of the usa/ this of the usa). The teacher had some exercise.... (be done/ to be done/ being done/ done) at home yesterday so that he can correct them today

Chọn đáp án đúng, giải thích lý do.
1. The climate of china is similar in many ways to.......( that of the USA/ the USA/ which of the usa/ this of the usa)
2. The teacher had some exercise.... (be done/ to be done/ being done/ done)  at home yesterday so that he can correct them today
3.  ..... (that/ what/ if/ unless) he was kidnapped by the iraqui guerrillas yesterday has been confirmed.