计算－（－11）的结果是（　　）

用显微镜观察植物细胞装片的同一部位．若想在视野中看到的细胞数目最多，应该选择的组合是（    ）

    My friend Tony is an American 1. He is ten years old. He lives2 his family in China now. There are 3  people in his family; his mother Mrs. Green, his father Mr. Green and his little sister Amy. He has a white cat. 4 name is Betty. Look！Amy is playing 5Betty. His father, Mr. Green, is watc­hing TV. His mother is doing housework. What about Tony? He is doing 6 Chinese homework. He can't 7Chinese well, but he likes Chinese very much. Tony's 8 works in a TV station. His father works in a school as an 9 teacher. Tony and his sister 10 to the same school.