1 . He had no opinions of his own but________ (simple) follow the others. （所给词的适当形式填空）

2 . People were walking, running, or ________(simple) sitting on the sandy beach. (所给词的适当形式填空）

3 . I had never seen Prince Hamlet do a back flip before! That was ________ (simple) incredible. (所给词的适当形式填空）

4 . It’s not __________ (simple) a matter of hiring more people. They also need to be trained. （所给词的适当形式填空）