第2题: [单项选择]According to the passage, which of the following is required for lactation A. Fat storage. B. Iron and calcium. C. Increased blood supply. D. A well-nourished placenta. 参考答案:A 答案解析:本题询问细节。由提示词“lactation”可在文中找到对应的语句“fat is accumulated within the body to store the energy necessary f
第30题: [单项选择]Blu-ray光盘使用蓝色激光技术实现数据存取,其单层数据容量达到了() A. 4.7GB B. 15GB C. 17GB D. 25GB 参考答案:D 答案解析:蓝光(Blu-ray)或称蓝光盘(Blu-rayDisc,缩写为BD)利用波长较短(405nm)的蓝色激光读取和写入数据,并因此而得名。而传统DVD需要光头发出红色激光(波长为650nm)来读取或写入