Mr Chen was puzzled（困感的） and a little suspicious（怀疑的）．He sat in the office and studied a letter apparently（看似）from Mrs Wang．the mother of one of the pupils in his class．There was something about it which worried him．

       "l don' t understand， "he said to himself．He shook his head as he circled four mistakes in the letter，"Mrs Wang is an educated woman．She wouldn't make mistakes like these even if she did write the letter in a hurry． "Mr Chen look out his class register（名册）and said to himself．"Yesterday was Thursday． Let me see， Ah， yes，I thought so．David was absent on Thursday last week and the week before． Hm． Why is he so often absent on Thursdays？ Was he really ill yesterday？Could it be a coincidence（巧合）？"

       Mr Chen stared at the register as if the answers to his questions were hidden in it somewhere．Then he took out a copy of the timetable（课程表） or his class．

       "I wonder …"he said to himself．"I wonder if his absence has anything to do with one of these lessons．"

       Mr Chen looked at the subjects for Thursday；Mathematics，English，P．E…He thought about P．E． He knew that the pupils had P．E．twice a week；once on Monday，when they usually played games on the school field，and once on Thursday，when they did exercises in the gym．

       Mr Chen glanced round the office to find Mr Long．the rather strict P．E． teacher，but he was not there．

       "I′d better have a chat with Long and David， "Mr Chen thought．

        The bell rang．"I can't do anything right now，" Mr Chen thought． "It's time to go to Class 2．I'll do it later on．"

       Mr Chen picked up his books and walked off to teach Class 2．

       Later，on Friday， Mr Chen spoke to Mr Long，the P．E．teacher． Mr Long agreed that it seemed strange for David to be absent so often on gym days．They thought about it for a while．

       "David is a good athlete（运动员）．"Mr Long finally said，"but he's afraid of heights．I was hard on him once because he wouldn 't climb more than a couple of metres up the rope．Do you think that's why he's been absent recently？"

       "Yes，I think so， "Mr Chen said，"I'm going to talk to him this afternoon before he goes home．"

       "Well， I've got a suggestion to make， "said Mr Long．"If he's scared of heights， he'd better come and see me after school．Quite a few people suffer from（遭受 ）vertigo． I'll be glad to help him．"

       "That′s very kind of you．"said Mr Chen．"I'll get him to come and see you on Monday or Tuesday．"

（1）The letter was sent to Mr Chen because David　　on Thursday．

A．was ill at home

B．didn't go to school

C． was absent from P．E．class

（2）Mr Chen was puzzled by the letter because　　．

A．David's mother sent him the letter

B．he couldn' t understand the letter

C．it didn′t seem to be written by an educated adult

（3）Mr Chen got the idea that David's absence had something to do with P．E． after he　　．

A． studied the timetable

B． studied the class register

C． talked with Mr Long

（4）The underlined word "vertigo"means　　in the passage．

A．身体疼痛

B．恐高眩晕

C．肠胃痉拿

（5）From the passage we know　　．

A．David didn't like P．E． classes

B．David didn't like Mr Long's being hard on him

C．David was afraid of heights