[求助]几道语法题---3

1)___ballet dancers learn five basic positions for the arms and feet.

A.      all of

B.      all

我不太懂all of .all再这的区别。

  这个知识点有过讨论，基本意见是of后应有明确的范围，如all of us, all of the students，而all则并不是这样。

2) The first city in the United States that put into effect major plan for the clustering

of government buildings was Washington,D.C

put前不应加was吗   

这是主动用法，不能加was.

3)In .the early 1900’s Roy Harris created and promoted a distinctly American style of

classical music and greatly influenced a number of composer in the United States.

Distinctly对吗，不应是distinct?

应是a number of composers

4) The eighteenth century witnessed the emergence of North American ports, particular Boston, New York, and Philadepjia, as major commercial centers within the British empire.

Particular怎么改，怎么解释改法

最好改为副词形式： particularly

5）many of species of milkweed are among the most dangerous of poisonous plants, while others have little, if any, toxicity.

Many of怎么改，为什么错？

同第一个知识点！

6）Generally, Abstract Expressionist art is without recognizable images and does not adhere the limits of conventional form.

Form没错吗，不应改为复数吗？

应该是复数！！

谢谢！！！