A

    Skin­diving is a new sport today. This sport takes you into a wonderful new world. It is like a visit to the moon. When you are under the water, it is easy for you to climb big rocks, because you are no longer heavy.

    Here, under the water, everything is blue and green. During the day, there is plenty of light. When fish swim nearby, you can catch them with your hands.

When you have tanks of oxygen on your back, you can stay in deep water for a long time. But you must be careful when you dive in deep water.

    To catch fish is one of the most interesting parts of this sport.

    What's more, there are more uses for skin­diving. You can clean ships without taking them out of water. You can get many things from the deep sea.

    Now you see that skin­diving is both useful and interesting.

请补写出空缺处的语句，与前两句构成排比，使语段意思连贯，风格统一。

    作一次心灵旅行，就以那一本本零落的古卷残页为车票，感受着穿越时空的欣喜。我与李白共攀蜀道，与辛弃疾拍遍栏杆，____，____。无论是漠北黄沙，还是江南水乡，我都一一留下足迹。

利用遗传变异的原理培育作物新品种，在现代农业生产上得到广泛应用．请回答下面的问题：

（1）水稻的穗大（A）对穗小（a）显性．基因型为Aa的水稻自交，子一代中，基因型为____ 的个体表现出穗小，应淘汰；基因型为____ 的个体表现出穗大，需进一步自交和选育．

（2）水稻的晚熟（B）对早熟（b）显性，请回答利用现有纯合体水稻品种，通过杂交育种方法培育纯合大穗早熟水稻新品种的问题．

①培育纯合大穗早熟水稻新品种，选择的亲本基因型分别是____ 和____ ．两亲本杂交的目的是____ ．

②将F₁所结种子种下去，长出的水稻中表现为大穗早熟的几率是　____ 　，在这些大穗早熟植株中约有　____ 　是符合育种要求的．

我国地势坦荡、草原广布的大高原是（ ）

—I like Japanese very much. What about you?

—Not especially. It’s difficult for me _______ .