Miss White has worked in the school for many years.The students all like her.She is a teacher of chemistry.She _1___ che

Miss White has worked in the school for many years.The students all like her.She is a teacher of chemistry.She _1___ chemistry from the lowest to the highest grades in the school.Sometimes the lower grades learn quickly,but sometimes they are very 2 ,and then Miss White has to repeat(重复) things many times.
This year,the first grade students have been studying chemistry for 3 weeks.One day Miss White asked the students,” What is water?4 knows?” There was a silence for some seconds and 5 sad.Just then one student raised his 6 .“Yes ,Nick?” said Miss White encouragingly （鼓励地）.He is not one of the cleverest children in the class,so she was 7 that he could answer.“Water is a liquid(液体) which has no colour until you wash your hands in it,” 1.A.learns B.helps C.teaches D.tells 2.A.free B.slow C.easy D.tired 3.A.a few B.a little C.few D.little 4.A.What B.Which C.Whose D.Who 5.A.though B.heard C.felt D.sounded 6.A.head B.leg C.hand D.hair 7.A.sad B.happy C.bad D.great