1.Everyone has his inherent ability ,________________ (只是很容易被习惯所掩盖).
　　2.The importance of traffic safety , _________________ (无论如何强调都不为过).
　　3.In my opinion , ______________ (打电动玩具既浪费时间也有害健康).
　　4.There is no doubt that ______________ (近视是一个很严重的问题)among the youth of our country.
　　5.According to my personal experience , ___________________ (微笑已带给我许多好处).

　　答案与解析：
　　1. which is easily concealed by habits
　　2. can't be overemphasized / can't be emphasized too much
　　3. playing video games not only takes much time but also does harm to health
　　4. near-sightedness is a serious problem
　　5. smile has done me a lot of good