标题: 大全446 [打印本页] 作者: falconcn 时间: 2009-8-13 17:36 标题: 大全446 446. It may be another fifteen years before spacecraft from Earth again venture to Mars, a planet now known to be cold, （划线部分为 again....to be，不知道为什么不能编辑) dry, and probably lifeless. (A) again venture to Mars, a planet now known to be (B) venture to Mars again, a planet now known for being (C) will venture to Mars again, a planet now known as being (D) venture again to Mars, a planet that is known now to be (E) will again venture to Mars, a planet known now as being