The number of people invited___fifty, but anumber of them ____absent for different reasons.

填入下面文段空白处的词语，最恰当的一组是（ ）如今，我们对大自然的感应 ① 不如一棵树。一棵树 ② 知道什么时候抽芽、开花、结实、落叶等， ③ 把它的生命经验记录在一圈圈或松或紧的年轮中， ④ 我们呢有许多年轻的孩子甚至不知道玫瑰、杜鹃什么时候开花， ⑤ 不要说 ⑥ 声音的体验中体会秋天来临了。 ①②③④⑤⑥

It is uncertain________side effect themedicine will bring about，although about two thousand patients have taken it.

You always spend only a little time on your study.You really _____ me down.— I’m sorry, Mum. I won’t do that again.

There’s______with your son’s ears. So don’t worry about him.