可惜楼上错了两题半.以下可作为标准答案：
Mr Smith is (busy) (writing) a book now.
They like playing (both) football (and) baskerball.
填空：
At the foot of the hill you could hear nothing, but the (sound/murmuring) of the running water.
It's (impossible/unthinkable）for him to cook dinner because he is only four years old. (原题目分成两句,严格来说是错的.)
I looked for my pet dog (everywhere) yesterday, but I didn't find it. (原题目有三个错.)