题目

It’s 2035. You have a job, a family and you’re about 40 years old. Welcome to our future life.Getting ready for work, you pause in front of the mirror. “Turn red,” you say. Your shirt changes from sky blue to deep red. Tiny preprogrammed electronics (智能电子元件) are rearranged in your shirt to change its color. Looking into the mirror, you find it hard to believe you’re 40. You look much younger. With amazing advances in medicine, people in your generation may live to be 150 years old. You’re not even middle aged!As you go into the kitchen and prepare to pour your breakfast在正方体ABCD-A1B1C1D1中，O是底面ABCD的中心，M、N分别是棱DD1、D1C1的中点，则直线OMA.和AC、MN都垂直B.垂直于AC，但不垂直于MNC.垂直于MN，但不垂直于ACD.与AC、MN都不垂直