----Who is going to ______ prizes  to  the  winners? ----- The headmaster,  of  course .

.The report shows that global climate change__________the drought in Southwest of China but ______ we need to make greater efforts.

________ to playing games recently，he is easy to feel sleepy in class.

.It is no use ______ after you know your failure.

Is it the years  _______  you worked in Africa as a doctor  _______  have a great effect on your literary works?