题目

阅读理解 Someone had given our name and phone number to a charity, and its staff were bringing us Christmas presents. I made sure the house was as spotless as it could be with four children living in it, as the due time drew near, I sat on the edge of the couch. Each time I heard a car, I jumped up to see if they were here. Each time it wasn't them, I was relieved, yet disappointed. Finally a huge car pulled into the driveway, and four people got out. Now I was embarrassed as well as grateful, excited and nervous. I greeted them with a smile. They made several trips and soon my living room著名呼吸疾病专家，中国工程院院士钟南山称SARS已经过去五年，仍不清楚其最终源头。SARS病毒与动物细胞相比最主要的区别是A.没有生命特征 B.没有蛋白质C.没有遗传物质 D.没有细胞结构