1. Metals _____   when they are heated.金属遇热则膨胀.
2. Our foreign trade____during recent years.近
  年来我们的对外贸易有所扩大.
3. The petals of many flowers____in the sunshine.
   许多花的花瓣在阳光中绽放.
4. There are no plans to____.
    没有扩建地方机场的计划.
5) It's said that the river____,where almost connects to other country.
    据说这条河延伸到很远的地方,几乎连接了另一个国家.