travel at half the speed of light

travel at half the speed of light at the travel agent office 还是 at the travel agent's office?缩写形式是 at the travel agent's at the travel (agent,agent's) officewhy 二选一 the party starts at half past ten 为什么加Sthe party starts at half past ten start为什么加S What's the time?It's at half past nine.改错 the next class begins at half past nine.begin 为什么加s 现在2011初一年级的英语书上的at the travel agent’s 为什么不是agent office 同样解释为旅行社,这两个有什么不同?at the travel agent’s和at the travel agent office以及为什么要缩写为travel agent’s 是in the half-time 还是on the half-time还是at the half-time the filmbegins at half past seven 翻译 The film begins at half past seven. 是in the half-time 还是on the half-time 还是at 他和half time 翻译 the last half of nineteenth century wintnessed the steay improvement in the means of travel let's make it(/)half past eight(on)the morning of June 21为什么不用at,in? let's make it(/)half past eight(on)the morning of June 21为什么不用at,in? shall we____ at the bus stop at half past two? 原句是Let's make it half past eight on the moring of June 21.那么,能不能说Let's make it at the gate of the school. 1.He often makes travel plans（ ）the Internet but he never gets information ( )it.A.in;onB.on;fromC.on;inD.from;in2.School f___ at half past three.(首字母填空,貌似中文是 学校放学之类的） 英语翻译It is said that spaceships can travel at half the speed of light by 2100.It might take us two or three days to get to Mars.Can you imagine humans' life on Mars?