bywater的精选

问题详情：Two-thirdsoftheearth         bywater.   A.arecovered B.iscovered  C.iscovering D.arecovering【回答】B知识点：动词语态题型：选择题...

问题详情：Inthefuture,peoplemaytraveltoMars(火星)bywater-poweredspaceship!Today'sspaceshipsarefineforgettingthingsintospace,buttheyarenotsogoodattravellinglongdistances.Thesespaceshipsburnchemicalfuels...