问题
不定项选择
如图所示,一个物体由A点出发分别到达C1、C2、C3,物体在三条轨道上的摩擦不计,则
①物体到达C1点时的速度最大
②物体在三条轨道上的运动时间相同
③物体到达C1的时间最短
④在C3上运动的加速度最小
A.①②
B.③④
C.①③
D.②④
答案
答案:B
如图所示,一个物体由A点出发分别到达C1、C2、C3,物体在三条轨道上的摩擦不计,则
①物体到达C1点时的速度最大
②物体在三条轨道上的运动时间相同
③物体到达C1的时间最短
④在C3上运动的加速度最小
A.①②
B.③④
C.①③
D.②④
答案:B
阅读理解,选择正确的答案。 | |
harvest (收获). In fall I can eat many different fruits: apples, pears, grapes and so on (等等). I can also eat fresh (新鲜的) vegetables. Fall is cooler than summer. I feel comfortable (舒适的). I am happy to see the wind blowing leaves off the trees. | |
1. My favourite season is _____________. | |
A. spring B. summer C. fall | |
2. We can eat many different _____________ in fall. | |
A. books B. fruits C. mittens | |
3. The weather in fall is _____________. | |
A. hot B. cold C. cool | |
4. The wind blows _____________ off the trees in fall. | |
A. fruits B. leaves C. vegetables | |
5. How many seasons are there in a year? | |
A. One. B. Three. C. Four. |