根据表中数据回答：假如让你架设一条输电线路，在铜线和铝线之间，你应选用____；假如要选用一根金属丝来做滑动变阻器的电阻丝，在镍铬合金和锰铜丝之间，你应选用____．

(1)The letter was ____  to my headmaster by a postman yesterday.

(2)I couldn't help ____  when I read the funny story.

(3)Of all the boxes, the one under the table is the ____ .

(4)The little boy fell down from the tree and hurt ____ .

(5)I am proud of my son because he is the____  of the sports meet.

某次植树，成活率达到105％

如图，一块边长为8米的正方形土地，在上面修了三条道路，宽都是1米，空白的部分种上各种花草．

①请利用平移的知识求出种花草的面积．

②若空白的部分种植花草共花费了4620元，则每平方米种植花草的费用是多少元？