【简答题】火力发电厂中测量主蒸汽流量的节流装置大多数选用哪几种节流元件?
【单选题】碘淀粉平板法检测青霉素酶时需要准备的试剂不包括下列哪个:
【单选题】火力发电厂中,测量主蒸汽流量的节流装置多选用
【单选题】碘淀粉平板法检测青霉素酶时需要准备的试剂不包括下列哪个:
【单选题】火力发电厂中,测量主蒸汽流量的节流装置多选用( ) 。
【判断题】纯弯曲梁横截面上的正应力在中性轴上为最大,离中性轴最远的点为零。
【判断题】纯弯曲梁横截面上的正应力在中性轴上为零,离中性轴最远的点最大。
【单选题】1995年与1949年相比,粮食总产量增长了3倍多,年均递增3.1%。
A.
The total grain output in 1995 more than quadrupled the 1949 figure, or an average increase of 3.1% a year.
B.
The total grain output in 1995 more than quadrupled, comparing the 1949 figure, or an average increase of 3.1% a year.
C.
The total grain output in 1995 more than quadrupled 1949, compared with its output figure, or an average increase of 3.1% a year.
D.
1995 and 1949 were in comparison that the former quadrupled the latter in terms of the total grain output figure, or an average increase of 3.1% a year.
【多选题】下列论述正确的是()。
A.
纯弯曲时,变形后的横截面保持为平面,且其形状,大小均保持不变。
C.
T字形截面的铸铁梁,其最大拉应力总是发生在最大正弯矩的横截面上
【单选题】碘淀粉平板法检测青霉素酶时需要准备的试剂不包括下列哪个