_______ does your mother do?
A:What
B:Where
C:How
若a﹣3b=4,则8﹣2a+6b的值为____ .
I'm an English boy. My name's ______ .
①用托盘天平称取5.6gCuO粉末
②用10mL水和10mL酒精配制20mL酒精溶液
③将50g溶质质量分数为10%的稀盐酸加热蒸发掉25g水,得到溶质质量分数为20%的盐酸
④用10mL的量筒取8.2mL水.