=2835÷27
=105
-- Anna, could you lend me this book, please?
-- I'm sorry. I it for only two days, and I haven't finished it yet.
若方程组4x+3y=5kx-k-1y=8的解中x的值比y的值的相反数大1,则k为( )
下列关于动物与其气体交换的场所,相对应的一组是( )
①草履虫﹣表膜 ②蚯蚓﹣体壁 ③缢蛏﹣鳃 ④鲫鱼﹣鳃 ⑤青蛙﹣肺和皮肤 ⑥蝗虫﹣肺 ⑦家鸽﹣肺和气囊.