问题 单项选择题

板的厚度一般为板的跨度的( ),且不小于80mm。

A.1/14~1/8
B.1/3~1/2
C.1/40~1/35
D.1/16~1/12

答案

参考答案:C

阅读理解
Laboratory work is your chance to learn science first-hand. It can be fun but you must be careful to prevent injury. Listen closely when your teacher reads and explains the rules before your first lab lesson.
LABORATORY RULES
Throughout the lesson
Do not enter the science lab without the teacher’s permission.
No food or drinks are to be allowed in the science lab.
Before the Experiment
Read all instructions carefully before every experiment.
Prepare all apparatus (仪器) and arrange them so that you will not knock them over while doing the experiment.
During the Experiment
If you are unsure of how to use any apparatus or how to operate, ask your teacher for help.
Never smell or taste chemicals unless your teacher gives permission.
After the Experiment
Wash all apparatus after use and return them to the places where they were.
Throw waste materials in proper waste baskets.
First Aid
Report all accidents to your teacher immediately.
If you spill (溅出) any chemicals onto your body of clothing, wash with plenty of water and report to your teacher.
小题1:Your teacher will probably tell you the rules above        the first lab lesson.
A.beforeB.sinceC.duringD.after
小题2:Before every experiment, you should       .
A.taste the chemicals first
B.clean all the apparatus
C.read all instructions carefully
D.report all the accidents to the teacher
小题3:When you are not sure how to use all apparatus,       .
A.try them on your ownB.put them back
C.ask your teacher for helpD.read the rules carefully
小题4:It is clear that you can       .
A.bring food into the lab
B.enter the lab anytime
C.smell chemicals as you like
D.learn science directly in the lab
小题5:If you get chemicals on the clothing, you can find ways to solve it in the part       .
A.Before the ExperimentB.First Aid
C.During the ExperimentD.After the Experiment
选择题