现在进行时中，为什么人们说she/he is having而不说she/he is hasing?
1 现在进行时的结构是助动词be（am，is，are）+动词原形的-ing形式。
2 正确说法：be having。
3 is hasing 这样的说法是错误的。
4 has 是have的第三人称单数，只用于一般现在时，和其他时态没有半点儿关系。你是把时态搞混淆了。
英语选择题，高手进，请说明原因
1. -We are in need of great help.我们非常需要帮助。
-___C____ ask them to do you a favor.为什么不叫他们帮忙？为什么不，用why not
A. How about B. Why don’t C. Why not D. Why didn’t
2. He is ___B___ the pride of his family, _____ the pride of all the Chinese people.
不仅……而且……not only……but（also）……
A. not, but B. not only, but C. either, or D. neither, nor
3. Even after hours of work his __A___ never seems to give out.
A. energy 精力 B. force 暴力 C. power力量 D. fuel 燃料
4. The accumulating evidence made the experts ___C___ the animal was a puma.
make sb do sth，使某人做某事
A. to think B. thinking C. think D. thought
5. Don’t hesitate any more. You have to __D___ a choice.别犹豫了，做个选择。
A. take B. receive C. give D. make
6. It was not until the thirteenth stroke ___A___ the bell stopped.在钟敲响13下之前铃已经停了。
A. before B. that C. when D. so that
7. Alf was ___D___ anything to his wife. 根据句意：他觉得太尴尬了所以没和他的妻子说任何话。
A. so embarrassed he said B. very embarrassed and said
C. very embarrassed, so he said D. so embarrassed he did not say
8. –David has made great progress recently.
- _____A___.表示某人也一样，So+和前文一样的语境谓语+人
A. So has his sister Julia
B. So his sister Julia has
C. His sister Julia has so
D. Has his sister Julia so
9. The room is so dirty. Whose __C__ is it to clean it, do you know?
A. task B. turn C. duty 职责，值日 D. round
10. ___B____the first sentence, the editor refused to publish the article.分次短语作状语，看后半部分的人和这个动词什么关系，主动用ing，被动用ed， 有明显先后顺序用Having ……。
A. Reading B. Having read C. He read D. Being read
11. The Shanghai you see today is quite a different city from what it _C_____.过去常常一种状态，used to be。
A. was used to B. was used to do C. used to be D. used to do
12. This book is not interesting. In my opinion, it is really not worth__A___.固定句型，be worth doing，值得做。
A. reading B. to read C. to be read D. being read
13. They had to work very hard to ___D___ all the money they had borrowed from the bank 3 years before.
A. get back B. take back C. hold back D. pay back偿还
14. –I’ve got some wonderful news. We’ve been invited to the palace ball.
-Really? ___C___.真的吗？我简直不敢相信！
A. I don’t believe so B. I believe not
C. I can’t believe it D. I don’t believe it
15. He explained the reason __B___ his being late to the teacher.固定搭配。
A. of B. for C. about D. in
16. Don’t you really want to go with Mr. Green? Why __C___ here for another
day?和第一题一个情况，为什么不……why not do sth
A. don’t stay B. not to stay C. not stay D. you not stay
17. Excuse me for breaking in, __B__ I have some news for you.两个不是相反的意思的句子连接，用and。
A. so B. and C. but D. yet
18. it’s not surprising that you are tired. __C___, you were up until 11 last night.
A. Instead 代替 B. In fact 事实上 C. After all 毕竟 D. What’s more而且
19. More natural resources should be __D___ use of to meet the increasing need of energy.
固定词组，充分利用，make use of
A. put B. brought C. taken D. made
20. Many people came to the meeting, _____ a number left early.这题说实话我不懂，我没搞清楚这句子的先行词是哪个。很多人到会，一部分人提前离开了。
A. to whom B. for whom C. of whom D. at whom
21. It is no good trying that method, because it won’t __A___.这方法没用，不会起作用，用work。
A. work B. use C. practice D. affect
22. It took Mary a long time to ___B___ a new dress at the store.
A. pick up捡起，顺路搭乘 B. pick out 挑选 C. take up D. take out
23. There was no __B___ that they had got the news. They all looked excited.算是固定词组，毫无疑问：There is no doubt that……
A. affair B. doubt C. matter D. problem
24. It is one thing to make a promise, but it is quite __B___ to carry it out.承诺是一回事，实现又是另一回事。
A. other thing B. the other C. others D. another
25. He must study English last night, __D__ he?注意，这题有情态动词must，真正的动词在must后面——study。前肯后否，后面用don‘t，因为是昨晚的事，所以用didin't。
A. don’t B. haven’t C. hasn’t D. didn’t
26. __C__their_____, ice cream is junk food because it has a lot of fat.固定词组
A. On, opinion B. In, opinions C. In, opinion D. On, opinions
27． I called __A__ his house, but he wasn’t in. then I called _____ him, but I couldn’t get through either.
call on sb，call at some place，固定词组。
A. at, on B. on, on C. at, up D. on, at
28. My uncle ___B___ until he was forty-five.一看句子翻译一下就知道是not until的句型。marry的用法要注意。
A. married B. didn’t marry C. was not marrying D. would marry
29. Though he is not rich enough, his wife often asks him for __B___.jewel是宝石类的总称，具体的用jewellery。
A. jewels B. jewelries C. a jewellery D. jewel
30. Our neighbor has ___D___ ours.和什么一样大的固定句型
A. as a big house as B. as big a house as
C. the same big house as D. a house the same big as
但是他的运气不好。 怎么说
However, he has no luck.
But he isn't lucky enough.
单句改错（特急）
1.for改成to
2.from改成of
3.careful改成carefully
4.having改成have
5.把in去掉
6.对不起，不确定
7.把for去掉
8.把第二个you改成your
9.把work改成walk
10.把crosses改成crossing
很正确，望楼主采纳