选词填空。 go off      take up      be reduced by      switch over      be filled with      suffer from      take place wake up      stand for      complain about 1.This program is boring.Can you the TV? 2.Being an explorer,Tom found that his life challenges and risks. 3.Many friends often to me their mothers. 4.The gun and she was killed. 5.WHO World Health Organization. 6.Mary isn’t well.She often headache. 7.The air conditioner  much space in the room. 8.Some elderly people are easy to but hard to fall asleep. 9.Some 300 papers were (提交)at the conference. 10.I heard a faint sound in the (远处).