一只钟表的分针长5厘米,经过一昼夜,分外尖端走过的路程是多少?
3.14×5×2×24,
=31.4×24,
=753.6(厘米);
答:分针尖端走过的路程是753.6厘米.
阅读短文,判断正(T) 误(F)。
We are playing a hide – seek game (捉迷藏). My name is Bill, where am I? I’m under the bed. My friend Tom and Tim are in the tree(在树上). My friend, Eric is in the big(大的) case. My sister, Gina is looking for us(寻找我们).
小题1:Bill is under the bed.
小题2:Tom and Tim are in the tree.
小题3:Eric is Bill’s brother.
小题4:Gina isn’t Bill’s sister.
小题5:There are (有) 5 children(孩子) playing the game (做游戏).
下列叙述中正确的是( )
A.SiO2制成的玻璃纤维,由于导电能力强而被用于制造光缆
B.浓硝酸储罐泄漏时,可以立即喷撒消石灰或烧碱处理
C.浓硫酸可用于干燥氢气、碘化氢等气体,但不能干燥氨气
D.分别充满NH3、HCl气体的烧瓶倒置于水中后液面均迅速上升,说明NH3和HCl气均易溶于水