单项选择题A.They often take place in her major industries.B.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.
单项选择题The author's assertions concerning the conditions that lead to the decay of the vacuum would be most weakened if which of the following occurred
单项选择题According to the passage, the author considers the reduction of energy in an empty region of space to which a real particle has been added to be
单项选择题Physicists' recent investigations of the decay of the vacuum, as described in the passage, most closely resemble which of the following hypothetical events in other disciplines
单项选择题Which of the following titles best describes the passage as a whole