用 so that/in oder that/ in oder to/ so a

问题：

用 so that/in oder that/ in oder to/ so as to。

1. She worked hard ____  everything would be ready in time.

2. Nothing more was heard from him ____  we began to wonder if he was dead.

3. He got up early this morning ____catch the first train.

4) ____ pass the exam, he studiedeven harder.