题目

Today’s young people are taking a more active part in online activities. Although the Internet can be  21  for students to collect information and communicate（交流）with their friends, teachers and parents are becoming more and more  22  about the unhealthy web content（网上内容）in the bar. They think that the birth of “Harm-free Internet Bars”（健康网吧）is  23  step to  24  teenagers.It was Sunday afternoon and there were not many  25  seats left in the Feiyu Internet Bar. A few  26  were found playing  27 . A person of the bar was walking around  28  1．下列关于细胞器的说法中正确的是（　　）A．人的成熟红细胞中没有线粒体，所以吸收葡萄糖的能量由细胞质基质提供B．细胞内催化合成胆固醇的酶附着于内质网上C．所有生物都有核糖体这种细胞器D．细胞内的溶酶体不可能消化细胞自身结构