大家讨论一下！！

yuying6239

1      Because of (its) vast tracts of (virtually) uninhabited northern forest, Canada has (one) of the lowest population (density) in the world.

这道题选择最后一个，可是我不太明白究竟错在哪里？

2      Early European settlers in North America (used) medicines (they) made from (plants native) to treat colds, pneumonia, and ague, (an) illness similar to malaria.

答案是c,是不是因为native 不应该做后置定语，而应该放在前面修饰阿？

3      Fish are the most ancient form of vertebrate life, and ( )all other vertebrates.

A from them evolved    B    evolved them         C  to evolve  D   they are evolved

答案是A ， 是介词短语前置，还是什么其他原因？

4    Most sand dunes are always in (motion) as wind pushes sand (upward) one side of each dune, over the top,( and )down (the other) side.

答案是B,这里upward有向上的意思，upwards 与其同意，不知道这句话是什么意思，以及要表达怎样的结构？

yuying6239

怎么没有人理我？？斑竹，斑竹，在哪里？

GREonlinetest

1.应该用复数吧

2.native形容词修饰名词应该在前

3.and引导并列句.且后面一个应为介词短语提前而倒装.故A

4.upward副词,应该用up吧

yuying6239

多谢指点！！

gre3333

yuyingMM，发贴请参照 TOEFL语法区发帖统一格式：

【发贴必读】----《语法区版规》提问格式说明★

此外，建议一题一贴，方便回答。

crossing

one of the + 复数名词+单数谓语