prevent的动作发出者是boundaries in the ocean, 不是sound

还是不明白何为“推理”问题，SC怎么推理呢？找出语法点，排除，选择正确答案，怎么个推理法呢

老师为什么是animal extinctions mark而不是这个事件marks

为什么是people save money，不是应该是这个行为save money吗？还是说C错在Those？

substitute A for B 用A替代B;;replace A with B，用B代替A;

D 为什么不能理解为supply pharmaceuticals and sources of building material and firewood

你把句子内容都补齐，than前后应该完全平行，这个句子应该是：

costs rose 2.8 percent in X, less than costs rose in Y.

这里后面的costs rose和前面完全一致，所以可以改写成

costs rose 2.8 percent in X, less than they did in Y.

我就想不明白，为什么赌场卖出去就一定继续做赌场了？？？这个assumption是怎么出来的？sell出去了可以做什么其他的场地啊
我的想法很奇怪吗？

逃离速度，说的就是撞完了，小碎片变慢又被引力吸引重新组合成了bubble pile。也就是说，这种大的彗星撞完了没事。1、2、3、4选项都没啥关系，就D一个意思。这里需要知道tendency是趋势，persist是持续存在。解题需要定位＋词汇。

为什么C不对啊，是因为a matter of concern吗

只有健康的人才会去做志愿者工作和内啡肽有什么关系呢，总感觉怪怪的

mark这道题的E

b选项算不算无主句？

1 question. 为什么这个地方 E 做独立主格就是对的，C 就是错的？

B:ensure + n.
ensure + that (后面直接跟陈述语气，不跟should be)
错误：ensure sb. to do sth.
B. ①with the intent to do sth. 固定搭配；②ensure sth. / ensure that svo. 无ensure sb. to do/be done的用法；③at least修饰对象错误；④to be put through含义错误，分配护士的时候，病人应该是已经被分过级了，所以应该直接用put(过去分词)。

DFirst, as mentioned above, "that are put through triage" incorrectly modifies "emergency room."

Second, "ensuring that at least one nurse should be assigned" is incorrect. If we are going to use "ensuring that," we should not follow it with "should." If we ensure that something happens, then it will definitely happen. "Should" implies that it *ought* to happen, and that is not the same thing.

D. it指代不清，make it easier for passengers结构不如E简洁。

though引导让步状语从句，其后面跟完整句子。

B. in 1959隔开了同位语drama and play和A Raisin in the Sun。
• this sentence starts with the modifier "The first commercially successful drama..."
...this modifier must be followed IMMEDIATELY by the name of the play ("a raisin in the sun" or "LH's a raisin in the sun").
"in 1959" is not a modifier of the play itself, so, that placement doesn't work.