选做题：从甲、乙两题中选做一题，如果两题都做，只以甲题计分。题甲：已知关于的方程的两根为、，且满足.求的值。 题乙：如图12，在梯形ABCD中
— Can you lend me your bike? — Yes. But you can only ________ it for one day. Because I’ll ride it to school the day after tomorrow. A. borrow B. to lend
I really think that people should __________ rivers to protect our environment. A. be prevented from polluting B. prevent from polluting C. be prevented to pollute
已知点A（2，0），抛物线C：x2=4y的焦点为F，射线FA与抛物线C相交于点M，与其准线相交于点N，则|FM|：|MN|=（ ） A．2： B．1：2 C．1： D．1：3
I want to know _______ do to help him. A. what I can B. what can I C. how I can D. how can I
有4瓶常用溶液：①BaCl2溶液，②NaCl溶液，③Na2SO4溶液，④CuSO4溶液。不用其他试剂，可通过实验方法将它们一一鉴别开来，鉴别出来的先后顺序可能是
