题目

C    Handshaking, though a European practice, is often seen in big cities of China. Nobody knows exactly when the practice started in Europe. It is said that long long ago in Europe when people met, they showed their unarmed hands to each other as a sign of goodwill. As time went on and trade in cities grew rapidly, people in cities began to clap each other’s hands to make a deal or to reach an agreement, This practice was later changed into shaking hands among friends on meeting or leaving each other. “Let’s shake (hands) on it” sometimes means agreement reached. Do the Europeans sh如图，已知线段AB，读下列语句，按要求画出图形：（1）延长AB到C，使BC=AB；（2）过点B画射线BM（BM与AB不在同一直线上）；（3）在射线BM上截取BD=12AC；（4）分别连接AD、CD；（5）用量角器等工具，求∠ADB+∠CDB的度数（精确到1度）．