小车静止在光滑水平面上,站在车上的人练习打靶,靶装在车上的另一端,如图所示.已知车、人、枪和靶的总质量为M(不含子弹),每颗子弹质量为m,共n发,打靶时,枪口到靶的距离为d.若每发子弹打入靶中,就留在靶里,且待前一发打入靶中后,再打下一发.则以下说法中正确的是( )
A:待打完n发子弹后,小车将以一定的速度向右匀速运动
B:待打完n发子弹后,小车应停在射击之前位置的右方
C:在每一发子弹的射击过程中,小车所发生的位移不相同
D:在每一发子弹的射击过程中,小车所发生的位移相同,大小均为 mdnm+M
①书山有路勤为径,____。
②有志不在____。
③哑巴吃黄连——____。
20世纪30年代,国共两党在陕西拜祭黄帝陵,共产党的祭文是:“维某年四月五日,苏维埃主席***、人民抗日红军总司令朱德恭遣代表林祖涵,以鲜花束帛之仪致祭于我中华民族始祖黄帝之陵。”该文中的“某年”可能是( )
根据短文括号内所给汉语意思,在空白处写出单词的正确形式。每空一词
Last ____ (圣诞节) Day, when I was at the street ____ (角落), a car ____ (经过) by. The car stopped in front of me. A woman looked out of the car and asked me ____ (有礼貌地), “Excuse me, could you tell me the right direction to the station?” Oh, my god! She was my old classmate. She used to be a shy girl. She didn’t ____(敢于)to speak in ____ (公众). But her English was good and she did well in the ____ (发音) and the ____ (语法). I____ (羡慕) her very much. Finally we had a happy ____ (谈话) and I told her the way to the station.