The world is a book,and those who don’t travel read only one page.That’s____I’ll go on a tour this summer.
| A.how | B.why | C.when | D.Where | 
William Tell hesitated to let his boy risk __ there with an apple on his head.
| A.standing | B.stood | C.to stand | D.to be standing | 
Crusoe found that nine savages seemed to be eating something which they ___ on the fire.
| A.have cooked | B.had cooked | C.to have cooked | D.being cooked | 
The half smile on the little hero’s face seemed to suggest that he was happy __ his life for his country.
| A.to give | B.giving | C.given | D.to have given | 
He forgot to turn off the light.So he went to bed with the light ___on.\
| A.to turn | B.turned | C.turning | D.turn | 
Asia is the largest continent, ___ one third of the earth’s land area.
| A.to cover | B.cover | C.covering | D.covered |