Twenty-two feet long and 10 feet in diameter, the AM-1 is one of the many new satellites that is a part of 15 years effort of subjecting the interactions of Earth’s atmosphere, oceans, and land surfaces to detailed scrutiny from space. d leelee e
A.
satellites that is a part of 15 years effort of subjecting the interactions of Earth’s atmosphere, oceans, and land surfaces
B.
satellites, which is a part of a 15-year effort to subject how Earth’s atmosphere, oceans, and land surfaces interact
C.
satellites, part of 15 years effort of subjecting how Earth’s atmosphere, oceans, and land surfaces are interacting
D.
satellites that are part of an effort for 15 years that has subjected the interactions of Earth’s atmosphere, oceans, and land surfaces
E.
satellites that are part of a 15-year effort to subject the interactions of Earth’s atmosphere, ocean, and land surfaces
答案是：e 题本身没有什么问题，但请请教一个知识点Earth’s atmosphere, ocean, and land surfaces 中ocean 应该用单数还是复数？或者 是表示泛指的时候单复数都可以？我当时是觉得洋跟大气不一样，应该是分个数的，所以觉得这里有点问题，后来又觉得 洋也是都连在一起的，也说的通。 反正是困惑了一小把，请明白人讲讲。谢谢 | 
