某班去看演出，甲种票每张24元，乙种票每张18元．如果35名同学购票恰好用去750元，甲乙两种票各买了多少张？

土地资源可以为我们的生活提供____。

无性生殖与有性生殖的本质区别在于有无生殖细胞形成．（判断对错）

-- I hear local people are trying to prevent some businesses building factories here.

-- Yes. They say the place may be polluted if some factories _______in the future.