题目

已知a，b，c为△ABC三边，且满足a2c2－b2c2=a4－b4，则它的形状为 A．直角三角形                   B．等腰三角形 C．等腰直角三角形               D．等腰三角形或直角三角形 答案：D 详细解答：∵ a2c2－b2c2=a4－b4，∴左右两边因式分解得 ∴   ∴或， 即或，所以三角形的形状为等腰三角形或直角三角形。完形填空Do you know Mr. King? He and his wife work in the_____office. She works harder than he does and so she is the _____ of their office. The man has to _____ her. But when they get home, the woman always feels _____ and doesn’t want to do anything. So the man does_____ of the housework. He does the cooking, washing and cleaning. And their children think his _____ is delicious.It’s Saturday today and they don’t go to work. Mrs. King _____ some friends to dinner. Now they’re talking in the sitting room. Mr. King is busy in the kitchen. They say he’s a _____ cook, too. This makes the man feel _____ .“ I’m abler (能干的) than her,” said Mr. King, “but her spouse (配偶) is abler than _____ !”【1】A. different B. same C. small D. their【2】A. teacher B. worker C. head D. hand【3】A. look at B. look after C. wait for D. listen to【4】A. tired B. hungry C. full D. free【5】A. little B. some C. most D. lot【6】A. flowers B. vegetable C. fruit D. food【7】A. invites B. tells C. makes D. does【8】A. bad B. good C. quick D. slow【9】A. sorry B. happy C. careful D. clear【10】A. them B. me C. mine D. ours