【简答题】Last year, a report by a committee of education experts said that a lot of American students cannot write well. The report noted the concerns of business leaders and teachers. The experts said that mo...
【单选题】It’s a mistake to think of Florida only __ its tourist attractions. A. by means of B. in terms of C. in connection with D. by way of
【单选题】a fire, hotel guests are askedto remain calm. A) In the of B) In the time of C) As a result of D) By reason of
【单选题】一对作减速传动的标准渐开线直齿圆柱齿轮,小齿轮为1齿轮,大齿轮为2齿轮,材料、热处理及齿面硬度均相同,则正常条件下传动时,两齿轮间产生的接触应力和弯曲应力关系为 ______。
【单选题】The success or failure of a product seems to be determined by a number of factors, one of which, the author emphasizes, is the consumer's perception of the product's______
B.
usefulness and durability
C.
need satisfying capability
D.
appearance and inner packing
【单选题】A rectangular tabletop consists of a piece of laminated wood bordered by a thin metal strip along its four edges. The suce area of the tabletop is x square feet, and the total length of the strip b...
【简答题】一对正确啮合的标准渐开线齿轮增速传动,1为主动,2为从动。两轮材料热处理相同,工作时轮齿根部危险截面上的弯曲应力的关系是σ F1 ()σ F2 ;接触应力σ H1 ()σ H2 。
【简答题】齿轮传动时,两轮轮齿的齿面接触应力σH 相等 ,而两轮轮齿的齿根弯曲应力σF 。