下列各句中，没有语病的一句是（　　）

Water is important to us. We can’t live _____ it.

Why not stop _______ a rest—Oh, it’s so exciting that I can’t stop _______ the kite.

________in the queue for half an hour, the old man suddenly realized he had left the cheque in the car. [ ]

She didn’t mention her troubles to Mr. Li，who might have helped her ______.