My name is Lucy and this is my grandfather. His name is Tim and he is my best friend. My grandfather is 64 years old and he is retired now, so he has much time to be and play with me. I love him very much and I know he loves me too.

    He lives with me, my father, my mother and my brother Kevin. We live in a big house. My grandfather is a very tall and strong man! Can you see me on his shoulders (肩膀)in this picture? He is really strong! My grandfather always knows what I want to do or to eat or what I feel inside! When I am sad, he makes me laugh with his funny faces. Every night before I go to bed, my grandfather tells me stories, and he even sings for me!

根据材料内容选择最佳答案。

①原子的种类   ②物质的总质量  ③元素的种类   ④分子的数目   ⑤物质的种类   ⑥原子的数目．

人们移栽植物幼苗的时候，往往在初期对幼苗进行遮荫，主要是为了使植物生长所需要的（  ）不受影响．