【判断题】工业粉尘危害很大,在我国,车间空气中有害物质的最高容许浓度是工作地点 空气中几次有代表性的采样测定不得超过的浓度
【单选题】David and Laura are probably ______.
【简答题】Listen to Imogen, David, Frank and Laura. What cities are they describing? What words helped you decide? Match the photos (a – d) with the cities.
【判断题】工业粉尘危害分大,在我国,车间空气中有害物质的最高容许浓度是工作地点空气中几次有代表性的采样测定不得超过的浓度。
【简答题】根据有效数字的运算规则计算下列各式: (1)213.+4.4+0.44 (2)1.576×3.286+1.7×10^-5-0.075×0.040 (3) (4)
【单选题】.五只等值电阻,如果串联后的等效电阻是1KΩ,若将其并联,则等效电阻为( )。
【判断题】工业粉尘危害很大,在我国,车间空气中有害物质的最高容许浓度是工作地点空气中几次有代表性的采样测定不得超过的浓度。
【单选题】David and Laura are probably__.
【单选题】五只等值的电阻,如果串联后的等效电阻是1kΩ,若将其并联,则等效电阻为( )。
【简答题】You are Laura, a communication assistant at Walmart, Inc. Your supervisor, David Oaks, needs to write a press release announcing the opening of a new Walmart store. You are going to leave a voice mess...