Unit 4 Life on MarsPeriod 4 Integrated skills&Study skills1.risk n.风险,危险2._开展;执行3._生病4._毕竟carry outget illafter all5.However,some other students were _ _ living there.然而,其他一些学生为住在那儿感到担心。6.They were even _ _ aliens there.他们甚至害怕那里的外星人。worried aboutafraid of 7.They thought aliens were dangerous and would _ people.他们认为外星人是危险的,而且会伤害人。8.Im not sure if its _ the risk.我不确定它是否值得冒险。harmworth 9.After all,humans _ already _ _ the Moon.毕竟人类已经去过月球了。have been to
