我国向世界范围内提供发射人造卫星的任务属于()
A.远洋运输服务
B.旅游服务
C.专业性服务
D.其他国际服务
参考答案:C
Sarah decides to move to Hainan because she thinks that the air there is much fresher than ___ here.
A.one
B.those
C.ones
D.that
肺泡的壁很薄,主要由弹性纤维构成