下列各句中，没有语病的一句是（ ）

The pretty girl is always busy helping her mother with the housework _________ I go to visit her family

It was not until all the milu deer ________that we realized we should build a natural park to protect them.

Sally took a photo of her friends while they_____computer games.

It is ___________ that theQing Tombs are influenced by the Ming Tombs, especially architecture and the way they are placed among the surrounding mountains and valleys.