．—The light in the office is still on．
—h，I forgot______.
| A．turning it off | B．turn it off | C．to turn it off | D．having turned it off |
106. Where are my keys? They seem to have ____.
| A．found | B．appeared | C．disappeared | D．Discovered |
105. The waters of this great lake, which is also the world's deepest, have been ____ by waste from a chemical factory.
| A．cleaned | B．cleared | C．dirtied | D．Thrown |
104. --- What do you do in the theatre?
--- I ____ plays.
| A．act | B．direct | C．perform | D．Watch |
103. Can you _____ the difference _____ American English and British English?
| A．tell; among | B．judge; between | C．tell; between | D．say; between' |
102. In the minority nationality the custom doesn’t ____ and has come down from generation to generation.
| A．die away | B．die of | C．die from | D．die out |