I have a pencil case. It is nice and big. It has many colours. There are two blocks on my pencil case. One is yellow, the other is orange. In my pencil case, there are pens, pencils, a ruler and an eraser. I like my pencil case very much
已知三角形的三边长分别是3,8,x;若x的值为偶数,则x的值有( )
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2011年5月8日—15日在荷兰举行世界乒乓球锦标赛,比赛所用的乒乓球是由一种叫胶棉材料制成.如图所示,这种胶棉材料具有较好的