答案一定要跟mortality直接相关

however是副词而不是连词，GMAT中连词只有FANBOYS (for, and, nor, but, or, yet, as)

所有格不能用代词指代

the goal of，不能用the goal to

the character of liquid

并列对象有误，证明了事实的，应该是“水乳胶球”和“画在陶器上的人的表现”，不应是“水乳胶球的发现”和“画作”。另外，主谓不一致错误同选项(B)。

2. laws后面没有什么必须不必须加to do一说的，是这样的，如果laws后面加-ing，那么-ing指的是laws的具体内容；加to do，则是表laws的终极目的。

还原倒装： Halley's comet caused such a worldwide sensation in no other historical sighting as in its returning of 1910-1911

主语是rock sample

水果和奶酪数量要一样，所以是要么都只有一种，要么都只有两种，一种的是C(6,1) *2，两种的是C(6,2) * C(2,2)

成本 买的时候所花出去的钱总和：70000 * 1.02 = 71400
收入 卖的时候自己能拿到的（卖掉的价格减去给中介的）： 82000 * 0.9 =73800
73800 - 71400 = 2400

K和A他们拿到邮票数量之比是：5：3；在K给了10张邮票给A之后，K和A之比：7：5. 问K比A多多少邮票？（前提是已经给了之后，还多多少张，一定要注意这句话）
K/A=5/3
K-10/A+10=7/5
解出：K=150 A=90 所以多60张 【此时不可以直接用 30*（7-5），因为x是给之前的每份的个数，给了之后这个变化了！！
所以150-10=K现有的140张
90+10=A现有的 100张
最后多40张

四种字母的：第一个字母有26中可能性，第二、第三、第四同理，乘法法则，所以为26^4
五种字母的同理：26^5
两种可能性相加：
26^5+26^4=26^5+26^4
=26*26^4+26^4=26^4 (26+1)=27 (26^4)

the two items should ALSO be parallel to the item at the BEGINNING of the sentence (i.e., "her work...", following "in addition to"). the context dictates that all three of these items are parallel - they have equal priority and are mentioned in exactly the same context - so you have to make ALL of them parallel.
this means that you have trouble if the latter two (the ones in the underline) start with "by", since the first one (outside the underline) doesn't.

in the correct answer, you have three absolutely parallel items:
her work ...
her discovery ...
her painstaking documentation ...

all three of these are nouns. all three are preceded by the possessive "her". there is absolutely no question that they exhibit better parallelism than the version you've suggested (although yours does improve somewhat on the given answer choice).

一定要回看原文，不能自己靠回忆脑补。。。

without 和 nor 不能连用，而且后面的the不能省略。

award A +B，award是及物动词。国家最高奖励没必要用过去式，用现在式更好。
关键是 long overdue究竟修饰谁——不能修饰medal,因为设置这个奖牌的目的不是为了早该奖励却一拖再拖这件事。应该修饰战后50年老兵们才被奖励勋章这整件事情（老兵早就应该被给予殊荣，却一直拖到现在，确实是long overdue了)

第二个是shipping fee....果然读题太粗心

#repost Ron's comment
in statement 1, both m and p are even. therefore, the remainder is even, so it's greater than 1.
done.
sufficient.

--
statement (2)
just pick various numbers whose lcm is 30.
notice the numbers selected above:
5 and 6 --> remainder = 1
10 and 15 --> remainder = 5 > 1
insufficient.