Silk ______ one of the primary goods traded along the Silk Road by about 100 BC.

The girl left home after quarreling with her parents, _____ them quite worried. [ ]

下列一组单词中，划线部分发音不同于其它三个的单词是_______。

I think I’m going to take a bus to thezoo.—–____________________

In a sports team each player has a clearrole，and there arefew occasions members areconfused or uncertain of their roles