船舶主柴油机气缸冷却水应最好()检查冷却水质量。 A.每天 B.每周 C.每半个月 发布时间:2018-04-30 10:22 │ 来源:www.tikuol.com 题型:单项选择题 问题: 船舶主柴油机气缸冷却水应最好()检查冷却水质量。A.每天B.每周C.每半个月D.每月
题型:单项选择题 相同温度下,体积均为0. 25 L的两个恒容密闭容器中发生可逆反应:N2(g)+3H2(g)2NH3(g) ΔH=-92.6 kJ/mol。实验测得起始时的有关数据如表所示:容器编号起始时各物质的物质的量/mol达到平衡时体系能量的变化N2H2NH3①130放出热量:23.15 kJ②0.92.70.2放出热量:Q 下列叙述错误的是( )A.容器①②中反应的平衡常数相等B.平衡时,两个容器中NH3的体积分数均为C.容器②中达到平衡时放出的热量Q=23.15 kJD.若容器①体积为0.5 L,则平衡时放出的热量小于23.15 kJ 查看答案
题型:单项选择题 如图所示的空间分为Ⅰ、Ⅱ、Ⅲ三个区域,各边界面相互平行,Ⅰ区域存在匀强电场,电场强度E=1.0×104V/m,方向垂直边界面向右.Ⅱ、Ⅲ区域存在匀强磁场,磁场的方向分别为垂直纸面向外和垂直纸面向里,磁感应强度分别为B1=2.0T、B2=4.0T.三个区域宽度分别为d1=5.0m、d2=d3=6.25m,一质量m=1.0×10--8kg、电荷量q=1.6×10-6C的粒子从O点由静止释放,粒子的重力忽略不计.求:(1)粒子离开Ⅰ区域时的速度大小v;(2)粒子在Ⅱ区域内运动时间t;(3)粒子离开Ⅲ区域时速度与边界面的夹角α. 查看答案
题型:单项选择题 完形填空。 A girl used to turn her cell phone off and put it by her photo on the desk every night before going to bed. This habit has been with her ever since she 1 the phone.The girl had a boyfriend. When they couldn't 2 ,they would either call or send messages to each other. They both liked this type of 3 . One night the boy really 4 the girl. When he called her,however,the girl's cell phone was off because she was already 5 . The next day,the boy asked the girl to 6 her cell phone on at night because when he needed to find her and could not,he would be 7 . From that day on,the girl began a new 8 . Her cell phone never 9 at night. Because she was afraid that she might not be able to 10 the phone ring in her sleep,she tried to 11 very alert. As days went on,she became thinner and thinner. Slowly,a gap began to 12 between them. The girl wanted to revive their relationship. On one night,she called the boy. However,what she got was a sweet female 13 :"Sorry,the subscriber you dialed is power off. " The girl knew that her 14 had just been turned off. After a long time,the girl had a new love. No matter how well they got along,the girl 15 to get married. In the girl's heart,she always 16 that boy's words and the night 17 that phone was power off. One night,the girl fell ill. 18 calling her parents,she dialed the new boy's cell phone. The boy was already asleep but his cell phone was still 19 . Later,the girl asked the boy," Why don't you turn your cell phone off at night?" The boy answered,"l'm afraid that if you need anything at night and aren't able to find me,you will be worried. "The girl finally 20 the boy.( )1. A. bought ( )2. A. meet ( )3. A. style ( )4. A. liked ( )5. A. sleepy ( )6. A. remain ( )7. A. delighted ( )8. A. friend ( )9. A. shuts down ( )10. A. see ( )11. A. leave ( )12. A. form ( )13. A. person ( )14. A. phone ( )15. A. pretended ( )16. A. realized ( )17. A. when ( )18. A. Apart from ( )19. A. on ( )20. A. refused B. used B. work B. communication B. missed B. tired B. exposed B. relieved B. habit B. shows down B. feel B. take B. fill B. voice B. power B. agreed B. understood B. why B. As a result of B. off B. married C. had C. eat C. emotion C. hated C. asleep C. leave C. scared C. career C. breaks down C. smell C. stay C. work C. image C. love C. decided C. remembered C. where C. In place of C. away C. visited D. left D. rest D. habit D. needed D. alone D. take D. worried D. hobby D. steps down D. hear D. hold D. disturb D. photo D. fan D. refused D. appreciated D. which D. Instead of D. in D. received 查看答案