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　　课时作业4　(A卷)

　　Ⅰ.品句填词

　　1．The teacher from ____________ I learnt most was Mrs.Zhu.

　　2．What's the name of the sport ____________ which you go in a boat?

　　3．Mathematics is the subject ____________ I am most interested.

　　4．This is the question ____________ we have had a discussion.

　　5．This is the house ____________ I was born.

　　6．This hall is five times ____________(big) than our classroom.

　　7．He doesn't study as ____________(hard) as his brother.

　　8．The ____________(hot) the air is, the more quickly it will rise.

　　9．The book is no ____________(heavy) than one half a kilo.

　　10．This book is ____________(difficult) than any other one here.

　　答案：1.whom　2.for　3.in which　4.about which　5.in which　6.bigger　7.hard　8.hotter　9.heavier

　　10．more difficult

　　Ⅱ.阅读理解

　　A

　　"The noise made by boats of whale watching tourists may be causing communication problems for the animals."British researchers said last week.

　　Whale watching is a popular tourist activity in places where groups of killer whales(虎鲸)live.Every day，dozens of boats filled with tourists go to watch the beautiful animals.Unfortunately，the engines of the boats make a lot of noise，and that may be causing problems for the whales，according to a report in the US science magazine Nature.

　　The whales travel in groups，and communicate with each other through sonic(声波的)calls that some scientists refer to as singing.The sounds of the boat engines may be creating too much background noise for the whales to be able to hear each other.

　　The researchers listened to recordings of whale calls made between 15 and 25 years ago，before whale watching became popular.These were compared to more recent recordings.

　　They found that the animals have started to sing for longer than they used to，like a person shouting to a friend across a noisy room.

　　It is believed that the whales are trying to communicate hunting or breeding information.Scientists said that，if this is prevented，the future of the world's whale population could be in danger.

　　"Animals become slow in mind and repeat themselves in noisy areas，"said Volker Deecke，a Canadian biologist."They have to say things twice or three times in order to be understood."

The killer whales studied were living off the coast of northwestern America.The number of