又到了班级大扫除的时间，卫生委员向班主任建议：公共区清理沟渠、搬运垃圾的工作尽量分配给男生，而教室窗户、黑板、课桌的清洁尽量分配给女生。卫生委员建议的合理性在于（    ）

完形填空
      This is my desk, and 1 books are on it. One is yellow and the other(另外的) is blue. You can see a 2 on the desk, too. The clock is red. My pencil case is3 the desk, too. A  pen, an eraser  and a ruler4in it. The pen is black. The5 is yellow, and the ruler is white.
    6 is my pencil? Well, it's under the desk. A baseball is under the7too. But the baseball isn't 8. It's my brother's. Is my computer under the desk, too? No，9isn't. Where is it? I can't10it in the room.

濒临亚洲的大洋，按顺时针方向依次是（    ）

在实验室中用锌、氧化铜、稀硫酸作原料，采取下列两条途径制取铜：
①ZnH₂Cu
②CuOCuSO₄Cu
若用这两种方法制得铜的质量相等，则下列叙述符合实际实验结果的是

在学习“物体运动状态改变的原因”时，老师做了如图的实验：具有一定速度的钢珠在水平面上能沿直线AB运动；如果在它的运动路径近旁放一磁铁，钢珠的运动路径将变成曲线AC．对该实验的理解．正确的是（    ）