汽轮机轴封系统的投入过程。

The following chart(表) shows some information about the student’s after-school activities in a middle school. 100% means all the students, 51%—99% means most students, 1%—50% means some students and 0% means no students.

Frequency(频率) of  Activity	Every day	Once or twice a week	Three or four times a week
Do housework	5%	75%	20%
Exercise	25%	10%	65%
Surf the Internet	15%	75%	10%

小题1:This chart is about the ______ of the students in a middle school.

A．numbers

B．lessons

C．hobbies

D．after-school activities

小题2: _________ of the students can take enough（足够的） exercise during the week.

A．65%

B．25%

C．10%

D．75%

小题3: If there’re fifty students doing housework every day, there will be ________students surf the Internet every day.

A．100

B．50

C．150

D．250