Emma is very busy in the moming. She gets up at half past five. After brushing her teeth, she ____. She usually does sports for thirty minutes. Next, she helps to make breakfast. At half past six, she eats breakfast. For breakfast Emma usually has bread and milk. She____ eats hamburgers. Hamburgers are unhealthy. Emma needs a healthy ____. After breakfast she____ her room. Then she goes to school. Emma usually____to school. She says walking is good for her.

如图，正方形ABCD中，点F在AD上，点E在AB的延长线上，∠FCE=90°．

（1）求证：△CDF≌△CBE．

（2）若CD=8，EF=10$\sqrt{2}$，求∠DCF的余弦值．

提倡“不使用一次性木筷”的出发点是（　　）