—________
A:Yes, please.
B:I like them.
C:Yes, it is.
甲:溶液 →BaCl2溶液 白色沉淀 →加足量稀硫酸 沉淀不溶解
乙:溶液 →加足量稀硫酸 无沉淀 →BaCl2溶液 白色沉淀
试评价上述两个方案是否严密,并分别说明理由:
See, your computer has broken down again! It doesn't ______ sense to buy the cheapest brand of computer just to save a few dollars.
如图,读“我国疆域示意图”,回答下列问题.