1.This is an _______ that will not be easily forgotten.
2.Please _______ me for my rudeness. I really do not know the custom here.
3.Water and air are _______ to human beings. We can not live without them.
4.When the airplane takes off, the passengers are told to _______ their seat belts.
5.This is not what we asked you to do. You can not get more pay for the _______ work.
6.My throat is _______. I cannot speak any more.
7.Many years ago, a lot of factories were _______ from big cities to the mountainous areas in case of war.
8.He said in his letter that he would _______ some photographs but I couldn’t find anything in the envelope.
9.Many English words are _______ from Latin.
10.I feel _______ to say that I can not believe what he said.