已知∠ABC．

（1）用尺规作图：作∠DEF，使∠DEF=∠ABC（不写作法，保留作图痕迹）；

（2）在上述作图过程中，得到哪些相等的线段？

    Mr. Black takes his daughter 1 a restaurant. They sit down, and there are a lot of  2 in the restaurant. They 3 for a long time, but no waiters come to their table.

    Mr. Black says, "I'm 4, I can't wait." He waits for a minute and says, "Now I am going to 5 something to get a waiter soon."

    He goes out of the restaurant and 6 the restaurant, "My 7is at a table in your restaurant, she 8 a red hat."

    The waiter finds the girl and he says to Mr. Black, "Yes, she's here. Do you want to 9 her?"

    "No," says Mr. Black, "But please give her something to eat quickly. She is very 10". Then he goes back to the restaurant. He is glad to see that a waiter is now at this table.

温室中绿色植物在阳光下生长，连续测定温室内的氧气含量，得到的图象应是（　　）

青春期，我们的身体悄悄发生变化的同时，我们的心理也发生着一系列的变化，下列对青春期心理变化正确的认识有（  ）
①青春期的心理变化是我们成长过程中不正常的现象
②青春期的心理矛盾构成了我们向前发展的动力，但处理不好也会成为我们发展的阻力
③青春期心理上充满矛盾是正常的心理现象，我们不必理睬
④我们应借助各种力量调控青春期矛盾的心理