A．A salesman.B．An assistant.C．A cab driver.D．A fee collector.

The passage is （)．A． a reviewB． a prefaceC． an advertisementD． an editoriai

A．An anthropologist.B．A teacher.C．A doctor.D．An inventor.

Which of the following is NOT written by Saul Bellow？A．Dangling Man.B．The Assistant.C．Herz

【C3】A．a questionB．a reasonC．an opinionD．an idea

【C10】A．an advantageB．a benefitC．an interestD．a profit

设A为n阶方阵 且 A =a≠0 则 An 等于（ ）。A. a B. 1/a C.an-1 D.