根据短文内容，从A～E选项中选出短文所需要的句子。
Being safe at school and in your everyday life needs knowledge. If you remember the following information，your life will be much safer.
●Always notice the environment around you. You shouldn't walk alone outside. ____ If anything dangerous happens，you can find them quickly.
●Don't use earphones(耳机) when running in the school yard or on the street. ____
●School bags should be carried towards the front of your body instead of pulling them on your back. ____
●If you are followed by a stranger(陌生人)，cross the street and go in the other direction(方向)，let the stranger know that you know he or she is there. Next，go and get help from others if it is necessary. ____You are safer on the street than you are in your home or in a lift.
●If you have to take a bus to a place far away，try to get to the bus stop a few minutes before the buses leave. ____ On buses，don't sit alone，sit behind the driver or with friends. Don't sleep.
A. Don't go home directly. B. You will keep yourself from the outside world and can be dangerous. C. Make sure where the public phones are. D. This stops a stranger from following you. E. When buses are crowded, it is easy enough for thieves to steal the things in your bags on your back. |
”的否定是“
” ；
为真”是“命题
为真”的必要不充分条件；
”的逆命题为真；
,则满足:
的概率为
；
