【单选题】发动机火花塞的电极间隙一般在()mm范围内。
【单选题】In the author's opinion, the absorption of immigrants into American society is ______ .
【判断题】市场竞争很激烈时,投标报价策略可以选择竞争型策略。()判断对错
【单选题】发动机火花塞的电极间隙一般在( )mm范围内。
【单选题】In the last paragraph, the author tells us the section on jokes and cartoons is ______.
【多选题】计算图示齿轮-连杆组合机构的自由度。当构件H为原动件时,该机构的运动是否确定?若存在复合铰链、局部自由度和虚约束,应指明。试指出下列哪些分析结果是正确的( )【图片】
B.
机构中无复合铰链,则 F = 3×5 – 2×5– 1 = 4
C.
机构中有复合铰链,则 F = 3×5 – 2×6– 1 = 2
【单选题】In the first paragraph, the author implies that writers' reactions to the development of railroads were ______.
B.
both positive and negative