1．There are a great number of natural resources in the desert, which remains to be exploited (开发)．
2．A nearsighted person can’t focus on distant(远处的) objects.
3．The river suddenly narrows(变窄) when it reaches the foot of the hill.
4．My colleague(同事) told me yesterday that he would resign and work for another company.
5．They were surrounded(围起来) immediately by small boys wearing school caps.
6．We took a raft downstream(随波逐流) along the Wanquan River, enjoying the beautiful scenery on both banks.
7．He built up wealth by trading(做生意) with other countries.
8．Most of the countryside in East England is very flat(平的)．
