A good way to pass an examination is to work hard every day in the year. You may fail in the examination if you are lazy for most of the year and then work hard only a few days before the examination. A few days before the examination you should start going to bed early. Do not stay up late at night learning things. Before you start the examination, read carefully over the question paper. Try to understand the exact meaning of each question before you pick up your pen to write. When you have at last finished your examinations, read over your answers. Correct any mistake which you see and make sure that you have not missed anything out.
小题1:“Stay up late at night” here means .
A．sleeping in bed
B．just sitting up without doing anything
C．walking about in the room
D．working far into the night小题2:The first thing to do after you get the question paper is to .
A．start to answer questions
B．work the difficult problems
C．have a look at the titles
D．read it very carefully小题3:Which of the following is TRUE according to the passage？
A．You must not hand in the examination paper before you check your answers.
B．You must wait till others point out mistakes in your paper.
C．You must first hand in your paper then correct the mistakes.
D．You must be the last to hand in your paper.
面的牙尖斜度不同，可分为（）