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（1）下列三种金属被发现、使用的先后顺序为：铜、铁、铝．金属大规模被使用的先后顺序跟（选填字母）____ （A．地壳中金属元素的含量 B．金属的导电性 C..金属的活动性）关系最大． （2）铁制品锈蚀的过程，实际上是铁与空气中的 和____等发生化学反应的过程．据有关资料报导，世界上每年因腐蚀而报废的金属设备或材料相当于年产量的20%～40%．保护金属资源，人人有责．请写出一条防止铁制品生锈的方法 ．目前世界上已有50%以上的废钢铁得到回收利用，其目的是（选填字母）____． A．节约金属资源 B．减少矿物开采，合理利用资源 C．防止钢铁生锈 （3）工人师傅切割铁板时，常用硫酸铜溶液在铁板上画线即可留下红色的印迹，此过程中发生的化学方程式为____． （4）某兴趣小组的同学从实验室收集到一桶含有FeSO 4 、CuSO 4 的废液，他们想从中回收和硫酸亚铁晶体，设计了如下实验方案．结合如图实验方案回答下列问题： 步骤①中，金属X是 ； 步骤②中，加入过量稀硫酸的目的是 ，该反应的化学方程式为 ．
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举一反三
【单选题】Choose the phrase that is closest in meaning to the underlined part. Since each individual frame of a film is equivalent to a discrete sampling operation, if the rate of spokes passing a given angle i...
A.
if the movie frame rate is too high with respect to the rate of spokes
B.
if the time interval between movie frames is too short with respect to the rate of spokes
C.
if the spokes move across a large angle to give the rate of movie frames
D.
if the rate of the movie frame is too low with respect to the rate of spokes
【单选题】Under an option contract, the right to buy an asset at a specified price for a specific time interval is______.
A.
short option
B.
long option
C.
call option
D.
put option
【单选题】对于一定温度下的金属丝杨氏模量,说法正确的是( )。
A.
只与材料的物理性质有关与材料的大小和形状无关
B.
与材料的大小有关而与形状无关
C.
与材料的形状有关而与大小无关
D.
杨氏模量标志着金属材料抵抗弹性变形的能力
【简答题】为了保证服务器中硬盘的可靠性,可以采用磁盘阵列技术,请问,使用磁盘镜橡的技术是( )。
【多选题】The model of your personal world is constructed by associations that link idea of _____, events, _____, and _____that co-occur with some regularity, either at the same time or within a relatively shor...
A.
circumstances
B.
actions
C.
reasons
D.
outcomes
【单选题】A constant force is exerted on a cart that is initially at rest on an air track. Friction between the cart and the track is negligible. The force acts for a short time interval and gives the cart a c...
A.
four times as long as that for the stronger force.
B.
twice as long as that for the stronger force.
C.
equal to that for the stronger force.
D.
half as long as that for the stronger force.
E.
a quarter of that for the stronger force.
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