__________ have known the results of the exam.

  A. It seemed to  B. It seemed to him to  C. He seemed that he    D. He seemed to

__________ have known the results of the exam.
  A. It seemed to  B. It seemed to him to  C. He seemed that he  D. He seemed to

__________ have known the results of the exam.

A. It seemed to B. It seemed to him to C. He seemed that he D. He seemed to

Doctors have known for a long time that extremely loud noises can cause hearing damage or loss．The noise can be the sound of a jet airplane or machines in factories of loud music or other common sound at home and at work．A person only needs to hear the noise for little more than one second to be affected．

       An American scientist has found that using aspirin （阿斯匹林） increase the temporary （暂时的）hearing loss or damage from loud noise．He did an experiment using a number of students at a university who all had normal hearing．He gave them different amounts of aspirin for different periods of time, then he tested their hearing ability．He found that students who were given four grams of aspirin a day for two days suffered much greater temporary hearing loss than those who did not use aspirin．The hearing loss was about two times as great．

       The scientist said millions of persons in the U．S．use much larger amounts of aspirin than were used in his experiment．He said these persons face a serious danger of suffering hearing loss from loud noise．

Doctors have long known that__________．

       A．one may lose his hearing when he hears a terribly loud noise．

       B．one may become deaf when he hears a loud noise．

       C．loud noises can cause damage to the hearing of the young people only

       D．common sounds at home are not harmful to the ear

This passage suggests that one’s hearing________．

       A．will be damaged even if he has heard a loud noise for only little more than one second

       B．will be damaged even if he has heard a loud noise less than one second

       C．will not be damaged if he has heard a loud noise for only little more than one second

       D．will not be damaged if he has little more than one second to get ready

One conclusion you can draw from the passage is that aspirin________．

       A．makes hearing damage from loud noise worse

       B．should never be taken more than four grams

       C．can damage one’s hearing when it is given more than four grams daily

       D．always increases hearing loss by two times

Millions of Americans are in danger of suffering hearing loss because they__________．

       A．take too much aspirin             

       B．often take air trips

       C．like listening to loud music        

       D．have too much loud noises at home and at work

The American scientist did his experiment in order to find ________．

       A．how much aspirin would affect a person’s hearing

       B．how much aspirin should be given in the treatment of the patients with hearing damage from loud noise

       C．whether aspirin would increase the temporary hearing damage from loud noises

       D．whether the people who had hearing damage should use aspirin

—Have you known Dr. Jackson for a long time?

—Yes, since she________ the Chinese Society.

A. has joined          B. joins                         C. had joined                 D. joined