单项选择题：衡量分析结果的主要质量指标是准确度和（）。A.精密度 B.系统误差 C.绝对误差 D

题型：阅读理解

Christopher’s mother now is sitting proudly and watching TV as Christopher is given the “Child of Courage” prize by his favorite TV star. This makes her remember the accident happened to them.

Christopher was sitting in the car with his mother, father, sister Rosie, 10, and brother Mac, 7, when his father drove onto a metal barrier(障碍物). Unluckily, the car fell down from a hill into a deep river. Christopher, then 12, swam through a broken window and got out for the fresh air. Then he realized his brother and sister were still in the car.

Christopher took a deep breath and swam back into the car. He saved Mac first, then he swam back to look for Rosie, who was under the cold, dark water, in the car. Christopher had to feel for her seatbelt because he couldn’t see anything in the water. He took the seatbelt off her, and went up for air. Finally he went back to pull her out of the car.

Christopher’s mother and father were thrown out before the car rolled down the hill. When his mother came back to her life, she looked for her children hurriedly. She could see Mac on the bank, but she couldn’t find the other ones. She was so worried. Then she saw Christopher come up out of the water like a dolphin with Rosie on his shoulder. She shouted excitedly to Christopher down to the river, “I’m so proud of you.”

The family called for an ambulance (救护车). It took Christopher’s father who was badly hurt to a nearby hospital immediately.

小题1:What is Christopher’s mother watching on TV?

A．Christopher is accepting a prize.

B．Rosie is singing with a TV star.

C．Mac is taking part in a TV show.

D．Her husband is lying in hospital.小题2:What happened to Christopher’s family?

A．They got lost on their way to a wild park.

B．Their car fell down from a hill into the river.

C．A man broke into their car and drove it away.

D．Their car broke down and caught a big fire.小题3:How do you feel about Christopher?

A．Brave.

B．Careful.