阅读下面材料,在空白处填入适当的内容或括号内单词的正确形式。
Snake dishes have become popular in_____ (recently) years. Snake meat in __
____(vary ) flavors (风味) can _____
___ (see) in restaurant ads very often. Eating snake seems to be now in vogue(盛行), and if you haven’t eaten a snake yet, you are considered “out of date”. But I wonder ______
____ all the trends are worth ___
___ (follow).
Some people may defend themselves by saying that snake meat is nutritious . But these people don’t realize that many parasites(寄生虫),_______ do harm to our health, are found inside snakes.
According ______ a survey, about 1000 tons of snakes are eaten every year in China and sometimes as many as 10 tons of snakes are served on dinner tables in Shenzhen in a single day!
These figures warns us that if no action is taken, _____ number of snakes will drop and make an increase in ___
_(mouse) and worms population, which will result in a decrease(减产) of crop output. Who will see such tragedy happen?
So let’s start not to eat snakes any more because “to protect the snake is to protect _________.”
幻方是古老的数学问题,我国古代的《洛书》中记载了最早的幻方——九宫图.将数字 分别填入如图所示的幻方中,要求每一横行、每一竖行以及两条斜对角线上的数字之和都是15,则 的值为 .
已知 , 满足方程组 ,则 的值为 .
综合实践活动课上,小亮将一张面积为 ,其中一边 为 的锐角三角形纸片(如图 ,经过两刀裁剪,拼成了一个无缝隙、无重叠的矩形 (如图 ,则矩形的周长为 .
如图,在正方形网格中,每个小正方形的边长都是1, 是 的外接圆,点 , , 在网格线的交点上,则 的值是 .
数学兴趣小组根据无人机测量学校旗杆高度,已知无人机的飞行高度为40米,当无人机与旗杆的水平距离是45米时,观测旗杆顶部的俯角为 ,则旗杆的高度约为
米.
(结果精确到1米,参考数据: ,