He made two expeditions to britain , in 55 bc and 54 bc .
他曾在公元前55年和54年两次远征不列颠。
The manned mars mission plans that came from this era would require three different expeditions .
这个时代的载人火星计划将需要三次不同的远征。
Military expeditions , rescuers in disaster zones , remote desalination plants and scientific-research bases might be willing to pay for such power from the sky .
军事远征，灾区救援人员，远程海水淡化厂和各种科研基地都可能愿意为这种太空能源花付费用。
Carrick and macgregor made several rural expeditions , including a month long trip to simbirsk province in 1871 .
