一台个人计算机的内存容量为256MB，也就是其内存有（） ["256兆字节","256兆字长","256兆比特","256兆个字"]
What is TRUE of pressure/vacuum valves? （） ["They are designed to provide for the flow of small volumes of tank atmospheres caused by thermal variations in a cargo tank","They should operate in advance of the pressure\/vacuum breakers","They should be kept in good working order by regular inspection and cleaning","All of the above"]
以下属于清洁生产的有（）。 ["产品设计时进行可回收设计","延长产品的使用寿命","对产品进行精美包装","物料封闭循环"]
占天然铀绝大部分同位素的铀-238可在下列哪些核反应堆中反应（）。 ["压水堆","钠冷快堆","气冷高温堆","铅冷快堆"]
张系国的作品《棋王》，而在80年代的大陆，也有一部同名的作品引起了很大的反响，它的作者是（） ["梁晓声","路遥","阿城"]
简述舌状绦虫病的症状和病理变化。
