实验室有一支读数不准确的温度计，在测冰水混合物的温度时，其读数为20°C，在测一标准大气压下沸水的…

_____at the town hall.the president was warmly welcomed by the mayor.a.to arrive b.on arriving c.arrived d.have arrived Many people gathered under the Town Hall clock.中的Town _____ at the Town Hall,the Queen was welcomed by the MayorA.On reachingB.At arrivalC.On arrivalD.At reaching选哪个?为什么? 嘿,你的益达. 是什么意思? 是你的益达 一项工程,甲乙合作需12天完成,乙丙两队合作需15天完成,甲丙两队20天完成,三队合修需几天? 求函数y=2x^2+x-1在[t,t+1]区间上的最大值和最小值 一项工程甲乙两队合作需12天完成,乙丙两队合作需15天完成,甲丙两队合作需20天完成,甲.乙.丙三队合作完成这项工程的一半,需几天 方程或方程组 It's about time we ______(pick up) the distinguished guests at the airport. 为什么一个小时是60分钟,一分钟为什么又是60秒,而一秒为什么是100微秒? Have you visited the Xiangguo Temple__the Song Dynasty?A.dated from;B.to date from;C.be dated from;D.dating from 一筐水果连筐重49kg,卖出这筐苹果的2/3后连筐重17kg,你知道筐的质量吗?快,现在就要! 有一些糖果在300粒到400粒之间 装成小袋后如果每袋12粒还剩下11粒如果每袋18个还缺一粒如果每袋15粒就有7袋各多2粒,这些糖果有多少粒? 诗人改诗的故事 一辆汽车立即刹车,从刹车开始计时,位移与时间关系为X=30T-3T2, 两段等分位移中时间分别是t1,t2 一箱糖果,每10粒一包或每12粒装异宝,都正好装完,估计这项糖果在的果数在350~400粒之间,共有糖果多少粒 英语翻译是什么啊 翻译：look after( )be good at( )of course( )good idea( ) all the mobile phone must be kept off,这句话中的keep off怎么翻译keep off有关机的意思吗?我查了一下好像没有啊 英语翻译Remember that our solar system is a single star,the Sun,with various bodies orbiting around it—nine planets and their moons,and asteroids,comets,meteors.But the galaxy has a lot of star systems—probably 100 billion of them.【 Okay?Th 一年有多少微秒 多少秒 多少分 多少小时 1微秒等于多少分钟 《宿新市徐公店》诗句是什么? 古诗宿新市徐公店的注释 古诗翻译 he is working hard for fear that he_______.a.should fall behind b.fell behind c.may fall behind d.falls behind为什么选a?是不是should就表示将来时呢?怎么用法, he is working hard for fear that he ___ A should fall behind B would fall behind为什么答案选A我觉得应该选B 意思是可能会落后,这个should怎么解释? He’s working hard for fear that he_____________ .A.should fall behind B.fell behind C.may fall为什么用should He is worked hard for fear that he.A.fails B.failed C.would fail D.fail He failed his exam,_ proves that he wasn't working hard ebough.A.what B.of which C.which D.this 想问问C不可以选么? 脱氧核糖有几个手性碳原子