在玻片上写上“6﹤9”，则通过显微镜观察到的图像应是（   ）

阅读下面的诗歌，完成小题。
                                                                                                                          绝句二首（其一）
                                                                                                                                      杜甫
                                                                                                                   迟日江山丽，春风花草香。

                                                                                                                   泥融飞燕子，沙暖睡鸳鸯。
      【注】此诗作于杜甫草堂。

如图，在平行四边形ABCD中，BD为对角线，点E、O、F分别是 AB、BD、BC的中点，且OE＝3，OF＝2，则平行四边形ABCD的周长为(    )

   Dogs like living with people. They are very friendly. They can do many things for people.   Some dogs help people to look after sheep, other dogs help them to find the lost children.① And some of the dogs can help the blind.(盲人)

   There is a kind of dog whose name is Seeing Eye Dog②. Now we can see this kind of dog all over the world. They are working for the blind. The Seeing Eye Dog is strong and easy to train(训练). He helps the blind to walk from place to place. Before a dog becomes a Seeing Eye Dog, he must be in a training school for about three months. First the dog has to learn to sit or stay when he hears the trainer's call. In his next lesson the dog learns to take his trainer across busy streets ③. The dog has many things to learn. 在……的末尾④the training, he must take tests. When he passes the tests, the Seeing Eye Dog will do things by himself.   Now he can help the blind people. The new master(主人) may be a man , a woman or even a child. It takes the dog and his blind master about a month learning to work and live together.⑤