课外阅读。

绝句

杜 甫

迟日江山丽，

春风花草香。

泥融飞燕子，

沙暖睡鸳鸯。

   Hi, I'm John. I had a good time last Sunday. I went to the nature park with my family, We saw the animals. The animals were so cute. I loved them verymuch. I took many pictures. In the afternoon, we went to the cinema. The film was so fun. Then we went home. My mother cooked good food for me. I was so happy. What about you? What did you do last weekend?

要测量河对岸建筑物AB的高度，在地面上选择距离为a的两点C、D，并使D、C、B三点在地面上共线，从D、C两点测得建筑物的顶点A的仰角分别是α，β（β＞α），则该建筑物AB的高为____ 

标有“220V 40W”的灯泡甲和“220V 100W”的灯泡乙，其灯丝长短相同，可发现____灯泡的灯丝较粗；若将这两个灯泡串联在220V的电源上，则____灯泡更亮一些（以上两空选填“甲”或“乙”）．