题目

Every fall, like clockwork, Linda Krentz of Beaverton, Oregon, felt her brain go on strike. “I just couldn’t get going in the morning,” she says. “I’d get depressed and gain 10 pounds every winter and lose them again in the spring.” Then she read about seasonal affective disorder, a form of depression that occurs in fall and winter, and she saw the light literally. Every morning now she turns on a specially constructed light box for half an hour and sits in front of it to trick her brain into thinking it’s still enjoying those long summer days. It seems to work. Krentz is下列实验操作正确的是（ ）A．用燃着的酒精灯去点燃另一支酒精灯B．稀释浓硫酸时，把浓硫酸沿器壁慢慢注入水里，并不断搅拌C．把氢氧化钠固体直接放在天平的托盘上称量D．实验时未经洗净的滴管可直接再吸取别的试剂