题目

Do you know the reason why we feel tired in the middle of a class? Maybe you would say it is because the teacher’s class is boring.1 ． Perhaps this is something you have not paid enough attention to or not yet noticed. Purpose of sleep2 ． Sleep helps our body heal（修复） , grow, and stay healthy. It also gives us energy, so we can be active all day. Doctors and health scientists say: When you close your eyes and need to rest, sleep is just the very best! This is more than advice. Sleep time Enough sleep is important to us. How much sleep do we need? New-born babies sleep most of Being hard-working is of the highest __________ to becoming successful. A．importantB．to be important C．importanceD．being importance