47. Either of^boys can do this well.

　　 Either of the boys can do this well.

　 [解析] either作主语时，其后如加of结构，后面的名词必须加定冠词，但在人称代词前则只能用either of us. 如：

　　　 Either of us can use this car.

46.There are many trees on either banks of the river.

　　 There are many trees on either bank of the river.

　[解析] either具有两个含意，其一是两者中随便哪一个，如：

　　 "Which do you prefer, tea or coffee?"

　 "I don't mind, Either will do."

　　 其第二个含意是两者中的每一个，如例句。但要注意的是either后加单数名词，而both后要加复数名词，如：

　　 There are many trees on both banks of the river.

45. No one of you could leave now.　　　　　　 (Ñ)

　　　 Not one of you could leave now.　　　　　 (P)

　　 [解析]no one不可加of结构，但not one of 则是正确的而且是强调句。

44.I don't want to drink hot tea. I want cold one. (Ñ)

　 I don't want to drink hot tea, I want cold tea .(P)

　 [解析] one只可用来代替可数名词，而不能用于不可数名词，但none则可以,如:

　　　 None of the news is good.

　　　 None of the girls are (is) here.

43. "Who won the game?"　 "None."　　　　　　　　 (Ñ)

　 　"Who won the game? ""No one."　　　　　　　 (P)

　 [解析]在简略答语中用who来提问的句子的否定答语是no one, 而用how many提问的答语是none,如："How many students

　are there?" "None."

42. "Do you have my dictionary?"　 "Yes, I have one." (Ñ)

　　 "Do you have my dictionary?" "Yes, I have it." (P)

　　 [解析] 在作简略答语时it用来特指上文中提到的物体，而one则泛指某一个，如：

　　 1) --"Do you have a dictionary?"

　　　 --"Yes, I have one."

　　 2) The books you bought yesterday are good one. (Ñ)

　　　 The books you bought yesterday are good ones. (P)

　　　 ones 是one的复数形式。

41．No one of them is my student.　　　　　　　 (Ñ)

　　 None of them is my student.　　　　　　　　 (P)

　 [解析] no one相当于nobody其意为没有人，其作主语时用单数谓语动词，如：

　　 No one expects you to be perfect, but we do expect you always to do your best.但no one不与of结构连用，但用none作主语时，其谓语动词是可单可复数，要视具体情况而定。通常要用of结构，不用of结构虽不是语法上的错误，但很不符合语言习惯，人们习惯于用：

　 　None of the boys is here.

　　 No one has jumped such high.

　　　 而不讲None has jumped such high.

40．Your bike is not as new as your brother's one. (Ñ)

　　 Your bike is not as new as your brother's.　　 (P)

　 [解析] 在my, John's, two, three等数词，both， some,后面不可直接加one或ones,但如果名词前有了形容词则是可以使用的，如：

　 I bought two dictionaries and two ones.　　　　 (Ñ)

　 I bought two dictionaries, and two good ones.　 (P)

39.　 Everyone should do one's best.　　　　　 (Ñ)

　　　 Everyone should do his best.　　　　　　 (P)

　　 [解析] 不定代词最多，其用法也最复杂。它们主要有：a few (few)， a little (little)， any， another，　 anybody， anything， anyone， all， both， either， everybody， each everyone，　 every one， many， much， most， neither， none， nobody， no one， nothing， one，other， some， somebody， someone， some one， something…这些代词每一个都有自己的用法特点和习惯用法，切记要一个字一个字地学习，不可以偏概全一致造成错误。one作代词时它的复数形式是ones,所有格one's,反身代词oneself, one在指某一人时相当于anyone,所以要用： one should do one's best, 但如one与别的词组成的其他词，或有修饰词短语时，则要用his/her， his/hers，　 himself/herself。

38. "English is difficult to learn." "So is it." (Ñ)

"English is difficult to learn.""So it is."　 (P)　

[解析]在仅仅是对对方意见表示同意时则不倒装。

　　 　与so有关的短语，如：

　　　 I told you so. 我告戒过你。

　　　 Everybody says so. 每人都这样讲。