下列各句中，没有语病的一项是（ ）

With the opening of the Qinghai-Tibet Railway, more and more people have chosen to travel Tibet, because it hasa(n) _____natural landscape. [ ]

swas alone at home, with lookingafter him.

下列各句中，加点的成语使用恰当的一项是(　　)

________ have you been at this school—Since 1990.