A:4.8 g
B:6 g
C:9.6 g
D:12 g
—The man at the gate _______ be our headmaster. He is always standing there every morning.
—No, it _______ be him. He is holding a meeting in the office now.
①把△ABC向上平移5个单位后得到对应的△A1B1C1,画出△A1B1C1,并写出C1的坐标;
②以原点O为对称中心,再画出与△A1B1C1关于原点O对称的△A2B2C2,并写出点C2的坐标.
(1)5-3+25+3-2 (2)25420-345+25