根据短文判断下列句子的正确(T) 与错误(F)。
Your home is a safe place, right? Think again.
Many serious accidents happen in people's homes.
Could you please prevent these accidents? Yes. Many accidents happen because people are careless.
So be careful! Here are some tips about safety.
Don't stand on chairs. Many people may fall off chairs and hurt themselves.
●Keep the floor dry, and you won't slip (滑) or fall.
●Be away from matches. Even a cigarette (香烟) can easily start a fire. Don't use water to put out fires.
Use salt instead.
●Be careful with knives! Many people cut them- selves in the kitchen. Never touch the broken bottles,
doors or windows. Glass can also cause the most senous cuts.
●Don't keep poisons (毒药) in the kitchen.
●Never use electrical appliances (电器设备) in the shower. Dry the floor before you use them, or electricity
can hurt you!
●Keep children away from hot water and hot drinks. They can be dangerous. But adults often forget it.
●Look through the peephole (门镜) when you hear the knock on the door. Don't let strangers in.
In a word, we should learn to protect ourselves and stay away from danger.
( )1. You must be careful when there is water on the floor.
( )2. Salt can't be used for putting out fires.
( )3. It's not safe for people to touch switches (电源插座) with wet hands.
( )4. Water and drinks can be dangerous for both children and adults.
( )5. Open the door at once when you hear someone knocking at the door.
，即以场源电荷为圆心的圆球面为等势面，面上各点电势相等，场强大小相等，但方向不同，所以A正确；如果正电荷有初速度，在电场力的作用下可能做减速运动，即从低电势向高电势运动，所以B错误；场强是反映电场力的性质的物理量，电势是反映电场能量性质的物理量，两者没有必然联系，场强为零电势不一定为零，电势为零场强也不一定为零，所以C错误；如果电场线是弯曲的，那么电荷在运动过程中，所受电场力沿所在点处电场线的切线方向，加速度方向与速度方向不一致，运动方向趋向电场力的方向，但与电场线方向不同，故D错误。