乌洛托品在合成、医药、染料等工业中有广泛用途,其结构式如图所示。将甲醛水溶液与氨水混合蒸发可制得乌洛托品。若原料完全反应生成乌洛托品,则甲醛与氨的物质的量之比为( )
A:1∶1
B:2∶3
C:3∶2
D:2∶1
把下面排列错乱的句子整理通顺。
____姐姐看见了,大声喊:“快把它放了,它是益虫。”
____大蜻蜓亮晶晶的两只眼睛,像小玻璃球,一对红翅膀不住地扇动,非常漂亮。
____我和姐姐发现一只大蜻蜓,落在一棵小树上。
____我悄悄地一捏,把它捉住了。
____我听了姐姐的话,想到益虫的好处,马上把它放了。
One summer evening I was sitting by the open window, reading a good novel. I was so 1 the story I was reading that I didn't 2 that it was getting dark. When I realized that it was too dark for me to read 3, I put the book down and got up to turn on the light. Just then I heard someone 4, "Help! Help!" It seemed to come from the trees at the end of the yard. I looked out but it was too dark to see anything clearly. Almost immediately I heard the cry again. It sounds like a child, but I could not 5what someone would be doing in our backyard, unless one of my neighbor's children had climbed a tree and had not been able to 6.
I decided that I should go out and have 7 in the yard, just in case someone was8. With a flashlight and a stick in my hands, I went out into the yard. Once again I heard the cry and this time there was no doubt that it came from the trees at the far end of the yard. "Who is there?" I 9 as I walked across the yard towards the trees. But there was no 10. With the help of my flashlight, I 11 all over that end of the yard, including the branches of the trees. There was no 12 of anybody or anything. I came to the conclusion that my 13 made fun of me, probably nothing is happening there.
I had to go back into the house and sat down to read my book again. Not long after that, I was 14 by the loud cry of "Help! Help!" This time it was from right behind me! I dropped my book and jump up. There, sitting on the table was my neighbor's large green and red 15.
中国六,七十年代乒坛上有过一颗新星,叫韩玉珍.她刻苦训练,曾获得过"练不倒的韩玉珍,打不垮的铜墙铁壁"的盛誉.她曾两度逼近世界冠军的颠峰,又两次垮了下来.第一次,因比赛前过于紧张临阵脱逃,用小刀刺破自己的手,却谎称有袭击破坏.第二次则在她已经领先两局的情况下,仅仅因为对手追上几分,心慌手软,败下阵来,她越怕越输,越输越怕,终于又抑制不住,谎称阑尾炎,腹部剧痛,想躲过比赛。这两件事成了国际乒坛丑闻.这说明她有( )
如图,C为线段AE上一动点(不与点A,E重合),在AE同侧分别作正三角形ABC和正三角形CDE,AD与BE交与点O,AD与BC交与点P,BE与CD交与点Q,连接PQ.有下列结论:①AD=BE;②AP=BQ;③∠AOB=60°;④DE=DP,其中正确的结论有 ( )