They are experienced porter(搬运工)who know how to the weight of the rocks they carry.
We offered these students a summer course , aimed _____ improving their spoken English.
England is rather short of arable land , so it is absolutely dependent upon other countries for her food __________.
The young man insisted that he _______ nothing wrong and ________ free.
_______ his arrival at the airport , the film star was recognized and soon surrounded by a group of film stars.
Let’s paint one side of the paper red, and _____ side black.