1.Haveyouthoughtofanewfuelforcars?（否定回答）No,wehaven'tthoughtofit().2.Maybeinthefutureallcarswillbeelectric.(同义句转换）Maybeallcarswillbeeletric()().

Question

1.Have you thought of a new fuel for cars?（否定回答）
No ,we haven't thought of it ( ).
2.Maybe in the future all cars will be electric.(同义句转换）
Maybe all cars will be eletric ( ) ( ).

Answer 1

1.yet
2.one day