题目

About ________ of the workers in the factory were born in the ___________.A．two-thirds;1970B．two-thirds;1970sC．two-third; 1970D．two-third;1970s 答案：B解析:表示几分之几，应该是基数词—+序数词的复数（单复数形式要根据基数词来决定），而in the +年后接s，故选答案B（本题满分为6分）先化简，再求值：（﹣4x2+2x﹣8y）﹣（﹣x﹣2y），其中x=，y=9999．