作为新生第一次报考自学考试该如何准备

然今卒困于此，此天之亡我，非战之罪也

卒：

I think a new era in the relationships between our two countries has _______.

A. set about

B. set out

C. set up

D. set in

垄断的主体是（ ）

A．经营者

B．经营者利益的代表者

C．经营者或其利益代表者

D．行业协会

Passage Two

Questions 26 to 30 are based on the following passage.

Scientists have established that influenza viruses taken from man can cause the disease in animals. In addition，man can catch the disease from animals. In fact，a great number of wild birds seem to carry the virus without showing any evidence of illness. Some scientists conclude that a large family of influenza viruses may have evolved in the bird kingdom，a group that has been on the earth 100 million years and is able to carry the virus without contracting the disease. These are even convincing evidence to show that virus strains are transmitted from place to place and from continent to continent by migrating birds.

It is known that two influenza viruses can recombine when both are present in an animal at the same time. The result of such recombinations is a great variety of strains constraining different H and N spikes. This raises the possibility that a human influenza virus can recombine with an influenza virus form. a lower animal to produce an entirely new spike.

Research is underway to determine if that is the way that major new strains come into being. Another possibility is that two animal influenza strains may recombine in a pig，for example，to produce a new strain which is transmitted to man.

According to the passage，scientists have discovered that influenza viruses______.

A. cause ill health in wild birds

B. do not always cause symptoms in birds

C. are rarely present in wild birds

D. change when transferred from animals to man