—Twice a month.

如图（1）至图（2），在△ABC和△ADE中，∠BAC=∠DAE=90°，点B、C、E在同一条直线上．

（1）已知：如图（1），AC=AB，AD=AE．求证：①CD=BE；②CD⊥BE．

（2）如图（2），当AB=kAC，AE=kAD（k≠1）时，分别说出（1）中的两个　②　结论是否成立，若成立，请给予证明；若不成立，请说明理由．

完形填空

     There is a saying, “No sports, no life.” Sports are very important to us. Sports help us to stay  1  and get good grades. Everyone in our class   2  sports. Our favourite  3  is PE. We only have PE lessons  4  a week, but we play sports every day. The most popular sport in our class is basketball. The boys enjoy  5  it, and many of the  6  like it, too. Another popular sport is football and there   7  a lot of football fans (球迷) in ourclass. When the weather is 8 , we often play ping-pong outside.We hardly ever (几乎不) play volleyball. We think it's  9. We have a basketball team. Our team often has friendship (友谊) matches (比赛) with teams from other schools. When there is a match, many of us go to  10  it. It's very interesting.

草长莺飞二月天，____。

我国要想赶超发达国家，关键要靠引进国外先进技术，这样可以节约时间和资金。（     ）