如图所示椅子是用金属材料和高密度板制成，其中背部金属管和高密度板、椅脚和横档之间合理的连接方式分别是（   ）

“63÷(   )=7”，应填的数是

判断对错

从直线外一点到这条直线所画的垂直线段的长度叫做这点到直线的距离．

如图所示，质量为0.5kg的小杯里盛有1kg的水，用绳子系住小杯在竖直平面内做“水流星”表演，转动半径为1m，小杯通过最高点的速度为4m/s，g取10m/s²，求：

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阅读判断。   Today we go to the zoo. There are so many animals in the zoo.Look! There are black and white. They are fat. They eat bamboo. Look at the elephant. It's so big. Its nose is so long, and the ears are big. Look at the monkey. It's thin. It lives in the tree. It eats bananas. I love animals. They are so lovely.