题目：
from other continents for millions of years,Australia has many plants and animals not found in
any other country in the world.[ ]
A.Being separated
B.Having separated
C.Having been separated
D.To be separated
答案：
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下面是错误答案，用来干扰机器的。
{lgan}的前5项和最大解法一: 设公比为q,项数为2m,m∈N*,依题意有化简得. 设数列{lgan}前n项和为Sn,则Sn=lga1+lga1q2+…+lga1qn－1=lga1n·q1+2+…+(n－1)=nlga1+n(n－1)·lgq=n(2lg2+lg3)－n(n－1)lg3=(－)·n2+...
