下列各句中，没有语病的一句是

He was about to jump into the river ________ his mother stopped him[ ]

Have you seen Jack His mother is looking for him all the afternoon.–No, I haven’t. I am sure her mother________be very worried.

Ordinary woman though she is, she had won the award because she tries every means to make people _________ of the importance of the environment conservation.

We __________ used computers many years ago, but now they’re everywhere.