140. It may be another fifteen years before spacecraft from Earth again venture to Mars, a planet now known to be cold, dry, and probably lifeless.B (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（A） (E) will again venture to Mars, a planet known now as being 我选了B。。答案是A。 哪位NN讲一讲，be known to be,be known as, be known for being 之间的区别 | 
