我国最大的岛屿（  ）

    Li Ming wants to buy some gifts for his mother and cousin in China. He goes to a shop. He buys two dresses for his cousin and some dishes for his mother. Now he needs some boxes. Jenny gives the boxes to Li Ming. Li Ming says thanks to Jenny and writes letters to his mother and cousin. Then Li Ming goes to the post office and buys four stamps. He thinks that his mother and cousin will like the gifts. He walks back to his house. He feels happy.

下列关于显微镜使用的叙述，正确的是（    ）