题干

水葫芦的危害:疯狂蔓延使很多水生生物处于灭绝的边缘。凤眼莲对其生活的水面采取了野蛮的封锁策略,挡住阳光,导致水下植物得不到足够光照而死亡,破坏水下动物的食物链,导致水生动物死亡。同时,任何大小船只也别想在水葫芦的领地里来去自由。不仅如此,凤眼莲还有富集重金属的能力,凤眼莲死后腐烂体沉入水底形成重金属高含量层,直接杀伤底栖生物。

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    Getting on the school bus, like the possible dangers around the home, getting on the school bus can also bring its own set of dangers. There are several important safety measures that parents should be aware of when it comes to bus safety.

    Parents should always make sure that someone is taking charge of children at the bus stop to make certain clear ground rules which are in place and are being followed—particularly rules that forbid horseplay in and around the street.

    Teach children to ask the bus driver for help in picking up anything they may have dropped around the bus, as children getting dropped articles are often hit by the bus or another vehicle because they are not seen by the bus driver or by oncoming traffic.

    Children should be asked to take five large steps away from the bus when they get it off, and make sure that the bus driver can see you and look you directly in the eyes to signal it is OK to cross the street. It is still very important that children also look both ways as they cross the street.

    Inform children that they must never speak to any stranger who talks with them first and that they must never accept a ride from any person unless their parents tell them directly that it is OK. Teach kids that adults should ask other adults for help, not kids. If an adult asks a kid for help, that child should get another adult.

    If for any reason a child feels uncomfortable or unsafe at the bus stop they need to bring it to a parent's or caregiver's attention.

Remember, planning ahead is always the best safety measure. Follow these rules and your family will be off danger!