除下列哪项外均是霍乱弧菌的定植因子（） A.鞭毛 B.毒素协同调节菌毛 C.脂多糖

蜗杆蜗轮机构是用于传递两交错轴之间的转动，两轴的交错角通常为（）。

A、30度

B、45度

C、60度

D、90度

One of the worst feelings in the world is trying your hardest at something but still falling short. In the case of schoolwork, studying for hours and bringing home disappointing grades may make you feel hopeless or helpless, but this is far from the truth. If you are dealing with disappointing grades, promise to change your study habits and you'll be amazed by the results.

Act Fast

The most important rule about dealing with disappointing grades is to act fast. Don't sit around and let them get worse, and definitely don't ignore them. Instead, admit that you need help and go in search of it soon. The faster you face up to the problem, the faster you can find a solution and see some results.

Tweak your routine

If you are studying hard and still dealing with disappointing grades, it's probably time to tweak your routine a little. Remember, if you keep doing the same thing all the time you'll undoubtedly keep getting the same results. Mix things up by asking for help, whether from a friend or fellow student, your teacher or a private tutor. Ask for help with the subject matter and tips for studying on your own.

Study Successfully

Of course it doesn't matter where you study or who you study with if you are studying the wrong things. Make sure that you are studying successfully by:

*Reviewing your textbooks.

*Looking over your notes from class.

*Taking new notes while you study.

*Investing in study guides.

*Answering all of the review questions you can find.

*Talking through events or concepts that are integral (整体) to your lessons.

Learn From Your Mistakes

If, after all of your changes and redoubling your study efforts, you are still disappointed with your grades, then it is time to figure out exactly where you are going wrong. Look over exam papers and assignments to see if you are having trouble with a particular kind of question (multiple choice, true or false, etc.) or concept. Examine your essays to see if you are explaining your ideas clearly and completely, or if it is the mechanics of your writing (spelling, grammar, etc.) that is letting you down. Request an appointment with your teacher and use this time to discuss your work and get his/her feedback as well.

Dealing with disappointing grades is something that every student will face at one time or another. It won't be fun, but take a realistic look at your attention in class, your study habits and your performance on past assignments and exam. Figure out where you are having trouble and dedicate yourself to fixing these problems.

51. The purpose of this passage is _______.

A. to introduce practical ways to solve worrying school problems

B. to persuade students to change their attitude toward schoolwork

C. to offer advice on how to improve academic grades at school

D. to emphasize the importance of dealing with disappointing grades

52. The underlined phrase to tweak your routine means _______.

A. to stick to the same study plan and seek help when possible

B. to mix things up before you work out a practical solution alone

C. to examine your everyday life to make room for self improvement

D. to make necessary alterations in your study habits and plans

53. According to the passage, it is desirable to _______.

A. adopt a great variety of successful study methods and work on your own

B. have a study partner who act fast to face up a problem and study successfully

C. find out your weak points by reviewing schoolwork and seek necessary help

D. make an appointment with your teachers and develop useful examination skills

54. The author of this passage is probably a(an) _______.

A. psychologist         B. examiner       C. parent         D. instructor

55. The author thinks that dealing with disappointing grades calls for _______.

A. a strong will power                     B. a down-to-earth attitude

C. creativity and dedication                 D. undivided attention

列入建筑安装工程造价内税金包括营业税等（）项费用。

A.3

B.4

C.5

D.6

根据国家税务总局《税收执法检查规则》的规定，执法检查主要有以下几种形式。（）

A、全面执法检查

B、专项执法检查

C、日常执法检查

D、专案执法检查