GWD4

cyx3271

GWD6-Q40:
It istheoretically possible that bacteria developed on Mars early in its history andthat some were carried to Earth by a meteorite. However, strains of bacteria from different planets would probably havesubstantial differences in protein structure that would persist over time, andno two bacterial strains on Earth are different enough to have arisen ondifferent planets.  So, even if bacteriadid arrive on Earth from Mars, they must have died out.
The argument ismost vulnerable to which of the following criticisms?

A.    It fails to establish whether bacteria actuallydeveloped on Mars.
B.     It fails to establish how likely it is thatMartian bacteria were transported to Earth.
C.    It fails to consider whether there were means other thanmeteorites by which Martian bacteria could have beencarried to Earth.
D.    It fails to consider whether all bacteria now onEarth could have arisen from transported Martian bacteria.
E.     It fails to consider whether there could havebeen strains of bacteria that originated on Earth and later died out.
题目都没有读懂的说 什么意思呢？？？

jerrylee90

http://forum.chasedream.com/GMAT_CR/thread-573338-1-1.html?postid=15169876&searchmode=TopicContent&searchtext=GWD6%20Q40