听力原文： Strikes are very common in Britain. They are extremely harmful to its industries. In fact there are other countries in Western Europe that lose more working days through strikes every year than Britain. The trouble with the strikes in Britain is that they occur in essential industries. There are over four hundred and ninetyfive unions in Britain. Some unions are very small. Over twenty have more than one hundred thousand members. Unions do not exist only to demand high wages. They also educate their members. They provide benefits for the sick and try to improve working conditions. Trade unionists say that we must thank the unions for the great improvement in working conditions in the last hundred years. It is now against the law fur union members to go on strike without the support of their union. This kind of strike la called the unofficial strike and was common until recently. Employers felt that unofficial strikes were most harmful because they could not be predicted. However, these unofficial strikes still occur from time to time and some unions have also refused to cooperate with the law. As a result, the general picture of the relations between workers and employers in Britain has gone from bad to worse.
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A. They often take place in the major industries.
British trade unions are more powerful.
C. There are more trade union members in Britain.
D. Britain loses more working days through strikes every year.