有6张卡片，每张卡片上分别写有不同的从1到6的一个自然数．从中任意抽出一张卡片，卡片上的数是3的倍数的概率是____ ．
I am very ____(累的) to look after two pre-school children at home.
______ is in the classroom . They are all on the playground
