这篇cloze 看看啊

这篇cloze 看看啊
It is very important to have healthy teeth.Good teeth help us to chew our food.They also help us to look nice.
How does a tooth go bad?The dacay begins in a little crack in the enamel (珐琅) covering of the tooth.This happens after germs and bits of food have__1___there.Then the decay slowly spreads inside the tooth.In the end,poison goes into the blood,and we may feel qmite ill.
How can we keep our teeth healthy?First,we ought to visit our dentist twice a year.He can fill the small holes in our teeth before they destroy the teeth.He can examine our teeth to check that they are growing in the right way,___2___,many people wait until they have toothache before they see a dentist.Secondly,we should brush our teeth with a toothbrush and fluoride (氟化物) toothpaste at least twice a day-once after breakfast and once before we go to bed.We can also use wooden toothpicks to___3____between our teeth after a meal.Thirdly,we should eat food that is beneficial to our teeth and our body,milk,cheese,fish,brown bread,potatoes,rice.raw vegetables and fresh fruit.Chocolate,sweets,biscuits and cakes are bad,especially when we eat them between meals.They are harmful because they ___4___out teeth and cause decay.
1.A stored B collected Claid D piled
2.A Unexpected B Certainly C Unfortunately D Generally
3.A drill B dig C clean D explore
4.A stick to B attach to C fix on D keep to
B C C A
我就想不明白了为什么是选这几个答案
1 C 为什么不对啊?
2.D 普遍地
4.B 依附在牙齿上的
我英语比较不好啊