Many people travel during the holiday season but do not make sure that their houses and homes ____ (protect). Crime goes up ____(rapid) during the winter and summer holiday seasons. Here are some things that you should keep in mind when you go on a holiday.

    Always give ____(strange) the feeling that you are at home. Have the snow ____(clean) off your stairs or out of your driveway during the winter season. You might ask someone to park ____ car in your driveway.

Tell your newspaper deliverer that you are not at home. ____(have) a pile of newspapers and other mail on your doorsteps tells people that are not at home, so you could also have a neighbor ____ a relative get your mail every day.

    Fix a timer in some of your rooms ____ turns lights on and ____during different time of the day. Some TVs also comes with a timer that you could set to be turned on during certain time. Have a sensitive light outside your house that ____(keep) thieves away when you are not at home.

若有理数a、b满足|a+6|+（b﹣4）²=0，则a﹣b的值为____．

金属及其化合物有广泛的应用．

（l）在0.2L由NaCl、MgCl₂、CaCl₂组成的混合液中，部分离子浓度大小如下图所示，回答下列问题：

①该混合液中含溶质MgCl₂的物质的量为____ 

②将该混合液加水稀释至体积为lL，稀释后溶液中Ca²⁺的物质的量浓度为____ 

（2）将8.0克氧化铜粉末，溶解于2L某浓度的盐酸中，再加入过量的铁粉，充分反应后过滤，同时收集到2.24L标准状况下的氢气．

①反应过程中涉及到的化学反应的离子方程式为____ 

②所用盐酸的物质的量浓度为____ 

（3）实验室有时用KClO₃和浓HCl制取氯气，其反应的化学方程式为KClO₃+6HCl（浓）═KCl+3Cl₃↑+3H₂O，该反应中的氧化剂是____ ，若有6mol Cl₂生成，反应过程转移电子的物质的量是____ ，有____ mol HCl被氧化．