用光学显微镜观察玻片标本时,对观察的生物材料的要求是[ ]
A.有平面结构的
B.形态不规则的
C.薄而透明的
D.有生命活力的
答案:C
单词拼写。
1. There is a big tree ______(在……后面)the house.
2. What is your mother doing in the ______(厨房)?
3. Don't let the little boy get close to the ______(浴缸).
4. When you see yourself in the ______(镜子), you'll find you are thin.
5. I'm going to the______(修车铺)to get my car back.
如图所示向我们展示了“守株待兔”这个成语故事.兔子撞上树木而死,其受到撞击力的施力物体是______,这个故事包含的物理道理是______.