如图，CD是Rt△ABC斜边AB上的高，CD=6，BD=4，则AB的长为（　　）

化学就在我们身边，它与我们的生活息息相关．

（1）“健康饮食、均衡营养”是青少年健康成长的重要保证，日常生活中食用的蔬菜和水果富含的营养素的____．

（2）酒精灯的火焰太小时，将灯芯拨得松一些，可使火焰更旺．其原理是____．

（3）下列电动自行车的各组件中，属于合成材料的是____ ．

a．橡胶轮胎   b．钢质车轮     c．塑料灯罩

（4）向一定量的AgNO₃和Mg（NO₃）₂混合溶液加入铜粉和锌粉，充分反应后过滤，得到溶液甲和固体乙，向固体乙中加稀盐酸有气泡产生，则溶液甲中含有溶质的离子是____ （用离子符号表示）．

根据句意，用括号内所给单词的正确形式填空。（一空一词）

1.They are organizing the____  (thirty-nine) sports meeting of their school.

2.The house____ (it) is very beautiful, but the river near it is much polluted.

3.The boy's dad was ____ (complete ) shocked when he saw that his son was playing with fire.

4.The news and talk shows may not be very exciting, but we can expect ____  (learn) a lot from them.

5.My grandfather's sunny character has a great ____ (influent) on me in my life.