For the line-source well,what are the additional assumptions？

听力原文：What are the advantages of E-mailing according to the passage?

What are the advantages of E-mailing according to the passage?

It is not only fast, but also can create____________and draw families closer.

A、The audiences choose to pay attention.

B、The audiences don't process a speaker's message exactly as the speaker intends.

C、What a speaker says is filtered through a listener's interests.

D、People pay closest attention to messages that related to their opinions.

听力原文： For the past few weeks we have been discussing national energy conservation alternatives for the future. Today I am going to talk about what one community is presently doing to conserve energy. The people of Davis California have succeeded in cutting their energy consumption by one third since 1973. The first energy saving action that was taken in the early 70' s was the legislation of strict building codes; all new houses in Davis must have the proper insulation so that heat will not escape unnecessarily in the winter. New houses also face north or south so that they will not be overheated by the sun in summer. The laws have had a definite effect. Since 1976, there has been a 50% saving in the amount of natural gas and electricity used in heating and air conditioning. There are other energy saving features about Davis. Buses, partially supported by the city, transplant university students throughout the area. There are twenty-four miles of bicycle paths and today there are twice as many bicycles as cars in the city. By reducing the available parking space the city council has succeeded in reducing the number of cars in the city every day. Another benefit of the reduced parking space is the greater number of small cars. People are saving gas because they are choosing not to drive or because they are driving fuel economic cars. Davis California has become an energy saving model for other cities. Time is up for today. Next week we will return to our regular topic of national energy alternatives.

What is the main topic of the lecture?

A．Bicycles and cars.

B．Building codes.

C．Energy conservation.

D．New housing construction.

A、The cause of the disease can be determined.

B、A variety of factors can be measured in an investigation.

C、The sample size is relatively small in the sampling survey.

D、There is less bias in the investigation.

l What are the similarities between air pollution and water pollution? You may use the subject-by-subject, point-by-point or sim-diff pattern. Record a 2-3-minute mini talk and submit the recording online as the homework. Make sure to use at least 3 transition words to make your idea logical and clear. You can refer to the expressions in the following chart. Similarity Difference A is the same with B A is identical with B A is similar to B Similarly Likewise Compared with… A is different from B A differs from B Whereas However On the other hand In contrast to…

what are the people in the picture?

What are the ways of preserving fossils mentioned in the discussion?[Clink on 3 answers. ]

A．Fossils can be preserved as moulds.

B．Fossils can be preserved through cauterization.

C．Fossils can be preserved through dehydration.

D．Fossils can be preserved as frozen dead bodies.

E．Fossils can be preserved in some chemical liquid.