题目

根据句意和首字母填单词。 1．Amy used to be quiet，but now she is very o________． 2．My biggest p_______ is that I am too shy． 3．If you want to be healthy，it's n_______ for you to eat some vegetables and fruit． 4．You must pay a_______ to your mistakes． 5．He wanted to be a doctor，but he became a teacher i_______． 答案：1. outgoing  2. problem   3.. Necessary  4. attention    5. instead如图，某人在山坡坡脚A处测得电视塔尖点C的仰角为60º，沿山坡向上走到P处再测得点C的仰角为45º，已知PA=100m，山坡的坡度为l∶2且O、A、B在同一条直线上，求电视塔OC的高度以及此人所在位置点 P的铅直高度（结果保留根号形式）。