日日人人_亚洲美女在线视频_av手机在线播放_国产大片aaa_欧美中文日韩_午夜理伦三级

With sufficient scientific information a manned trip to Mars should be _____.

A. obtainable B. potential C. considerable D. feasible

With sufficient scientific information a manned trip to Mars should be _____.

A. obtainable    B. potential    C. considerable     D. feasible

With sufficient scientific information a manned trip to Mars should be _____.

A. obtainable       B. potential       C. considerable D. feasible

 With sufficient scientific information a manned trip to Mars should be ________
A. obtainable       B. potential       C. considerable D. feasible

 With sufficient scientific information a manned trip to Mars should be ________

A. obtainable       B. potential       C. considerable D. feasible