题目

A person has to be sixteen to drive, seventeen to see certain movies, and eighteen to vote. People can get terrific discounts on all sorts of stuff－provided they’re over sixty-five. Everywhere we look there are age limits that define what people can and can’t do. But creativity has no boundaries, no limitations. Anyone can invent. And they do. Inventors are popping up at the youngest ages. Sitting in the car waiting for her mom to return from shopping, Becky decided she might as well try to finish her math homework. But it was growing dark and getting hard to see the paper. “I didn’t在北方的冬季，常见的几种物态变化现象中，属于凝华的是（　　）A．室外冻冰的衣服变干B．房间窗户玻璃的内表面出现冰花C．湖面结了厚厚的一层冰D．正在跑步的人，口中呼出“白气”