【判断题】在做动物照影实验时要穿铅衣来防止辐射。()
【判断题】Jf2B4309操作票上的操作项目必须填写双重名称,即设备的名称和位置。
【单选题】In such cases, either chemical methods of separation with the general techniques of chemical analysis must be applied in order to eliminate the interfering effects of these constituents or, as is comm...
【单选题】Most reproduction of plants is accomplished through germination of seeds, but sometimes this is not possible or the process is too lengthy for commercial purposes. In these cases, man steps in and use...
【单选题】The fish was caught _______.