I find the days have already slid away f

题型:选择题

问题:

I find the days have already slid away from me, like a drop of water from the point of a needle _____ into the ocean.   [ ]

A. disappeared    

B. disappearing  

C. do disappear  

D. was disappeared

考点:现在分词
题型:选择题

如图所示,固定的凹槽水平表面光滑,其内放置U形滑板N,滑板两端为半径R=0.45m的1/4圆弧面.A和D分别是圆弧的端点,BC段表面粗糙,其余段表面光滑.小滑块P1和P2的质量均为m.滑板的质量M=4m,P1和P2与BC面的动摩擦因数分别为μ1=0.10和μ2=0.40,最大静摩擦力近似等于滑动摩擦力.开始时滑板紧靠槽的左端,P2静止在粗糙面的B点,P1以v0=4.0m/s的初速度从A点沿弧面自由滑下,与P2发生弹性碰撞后,P1处在粗糙面B点上.当P2滑到C点时,滑板恰好与槽的右端碰撞并与槽牢固粘连,P2继续运动,到达D点时速度为零.P1与P2视为质点,取g=10m/s2.问:

(1)P2在BC段向右滑动时,滑板的加速度为多大?

(2)BC长度为多少?N、P1和P2最终静止后,P1与P2间的距离为多少?

题型:选择题

记账式国债是指经中国人民银行批准在商业银行柜台发行和交易,以()登记债权的政府债券。

A、纸质凭证

B、电子媒介

C、记账方式

D、纸或电子媒介

题型:选择题

I got a job teaching special education at a school in Coachella, California, a desert town about 170 miles from home. It was no (1) job. Street gangs (2) around the school after dark.

"Be careful, " Dad warned me during one of my frequent weekend (3) home. He was concerned about my living (4) , but I needed to be on my own.

One evening, I stayed after school to rearrange my classroom. (5) , I turned out the light and closed the door. Then I (6) toward the gate. It was (7) ! I looked around. Everyone had gone home.

After (8) all the exits, I found just enough (9) to squeeze under a gate in the back of the school. Then I walked toward my car, parked in a field behind the building.Suddenly I heard voices. I (10) around and saw at least eight boys following me. (11) my pace, I reached into my shoulder bag to get my key. I (12) all over the inside of my handbag. But the key wasn’t (13) ! Dear Lord, please help me, I prayed (14) . Suddenly, my fingers touched a loose key in my purse. I didn’t even know if it was for my car, but I took it out and (15) it. It worked!I opened the door, slid in and locked it—just (16) the teenagers surrounded the car. Trembling , I started the engine and (17) away. When I returned to my apartment, the phone was ringing. It was my Dad. I didn’t tell him about my experience; I didn’t want to (18) him. "Oh, I forgot to tell you!" He said, "I had a (n) (19) car key made and slipped it into your purse—just (20) you ever need it.

4()

A.happily 

B.far 

C.nearby 

D.alone

题型:选择题

虽然美发操作工艺发展变化较快,但是吹风的技能始终不能替代()。

题型:选择题

健康的等级状态包括死亡、疾病、健康不良、______、健康良好、______、完满康宁。

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