rate只能是high/low,不能是fast,suppliers are growing fish twice as fast as their natural growth rate错误,改成suppliers are growing fish twice as fast as they grow naturally
1. ABC的in addition to and besides 都是介词用法,后面接名词或者名词成分,例如动名词和从句。最大的错误是两个用语后面的名词成分都必须在句子中与一个成份形成实际意义上的语义逻辑上的平行关系。而ABC里的possibility在后面句子中找不到对应的词。
2. ABC的It指代问题,应该是leaves,复数
3. D and E, D的possible +动名词 preventing and inhibiting没有E的possibly preventing or inhibiting好,原因有二,一是 D中and不如E中or在语义逻辑上更准确。Ron说这两个词是mutually exclusive,不可能用and同时发生,肯定是or。同理还有一个句子里有damage and destroy,也是应该用OR,而不能用and;二是 D中possible修饰preventing 以及inhibiting,应该用副词形式修饰这两个动作。若用形容词的possible,就用prevention更合适。
错选了B,实际上文段中提到All the recorded staple crops grown in western Africa were introduced from...,所以这个选项可以直接排除
A选项:会不会在米饭和yams被人知道之前有过其他的主食[说明可能农业社会早就开始了]
C选项:outside of是错误的,不讨论西非之外的情况
DE都不在讲主食,与结论无关
percentage与number,average的区别