单选题 Accidents can happen indoors. Many young children are accidentally hurt when playing in their homes. How do these accidents happen?
A housewife is a busy person. She had to do all the work in the house. Sometimes she is careless. She puts a pot of hot water on a table. A little child can reach it. Then she goes out of the room. The little child reaches up and drags the pot towards him. The hot water may spill over him and scald him. The mother hears the cry of pain and rushes into the room, but it is too late. The child must be taken to the hospital at once.
Accidents like these ought not to happen. We must not put the pots and pans full of hot water or other hot things in the reach of small children. And we must not leave the small children by themselves.
All things which can cut are dangerous. Sharp knives and scissors should be put away out of the reach of children.
Electricity is always dangerous, it can be useful but it can also kill us! You should never touch any electric appliances if they are switched on. Switch them off first.

【正确答案】 B

【答案解析】[详细解答] turn down是“调低音量”之意，turn off是“关掉”之意，turn over是“翻转”之意。switch off是“关掉”之意。因此选择B。