题目

His wife’s death disturbed the _______（平衡）of his mind. He didn’t know what to do.   答案：balance  （10·淮安）如图所示，钢制弹簧作为健身拉力器的构件，主要利用钢铁较好的   A．导电性                                 B．导热性   C．弹性                                   D．绝缘性