单项选择题A.they are more responsibleB.they are more self-reliantC.they know how to workD.they are more sophisticated
单项选择题A.isolationB.insecurityC.povertyD.crowdedness
单项选择题A.The spacecraft will fly direct to Mercury.B.The spacecraft will fly three times past Mercury.C.The spacecraft was launched a week later than planned.D.There is no specific task for this journey.
单项选择题A.they like investmentsB.they like challengesC.they like the jobD.they like the rural area
单项选择题A.sixB.nineC.twelveD.sixteen