问题
填空题
根据句意和汉语提示，在空白处填入适当的单词。
1. —I like this camera! Is it yours?
—Yes, I ________ (花费) 1,200 yuan on it last year.
2. —How often do you play badminton with your classmates?
—________ (一次) a week.
3. —I am worried I'm getting fatter.
—You should eat _________ (少) food and do more exercise.
4. Huaguo Mountain has become the _________ (象征) of Lianyungang.
答案
1. spent 2. Once 3. less 4. symbol
，用细绳相连，跨过光滑的定滑轮，A置于倾角为
=15°斜面上，B悬于斜面之外，处于静止状态.现在向A中缓慢地加入沙子，整个系统始终保持静止，则在加入沙子的过程中（ ）
Mg