用括号内所给单词的适当形式填空。
1. This cake is very ________ (nice), but that one is ________ (nice) than this one.
2. Living in the country is much ________ (exciting) than living in the town.
3. All of us need ________ (study) hard .
4. Which goes ________ (quickly), the bus or the car?
5. Who is ________ (young) in your class?
6. A cow is much ________ (big) than a sheep .
7. The new book is ________ (easy) than the old one .
8. This park is________(beautiful) of all .
9. Uncle Wang is very ________(friend) and________(help). He often helps us.
10. Which do you like ________(well), cats , dogs or chickens?
1. nice, nicer
2. more exciting
3. to study
4. more quickly
5. the youngest
7. easier
8. the most beautiful
9. friendly, helpful
10. best
一质点在x轴上并只朝着x轴的正方向运动,各个时刻的位置坐标如下表,则此质点开始运动后:
t/s | 0 | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 |
x/m | 2 | 4 | 6 | 8 | 8 | 8 | 12 | 16 | 20 | 24 |
(2)质点在8s末的瞬时速度为______m/s;
(3)质点在0到18s这段时间内的平均速度______m/s.