船舶干货舱自动探火和报警系统多采用烟气管道（）探测器。A．感光 B．光电感烟 C．离

慢性肺心病最常见的心律失常是（）

A.室性早搏

B.心房纤颤

C.心房扑动

D.室性心动过速

E.房性早搏和室上性心动过速

表示关系a≤b≤c的C语言表达式为( )。

A．(a＜=&&(b＜=

B．(a＜=and(b＜=

C．(a＜=b＜=

D．(a＜=&(b＜=

采用支导线测定界址点坐标的，导线边最多可以是（）。

A、二条

B、三条

C、四条

D、五条

The inside dimensions of a rectangular wooden box are 6 inches by 8 inches by 10 inches. A cylindrical cannister is to be placed inside the box so that it stands upright when the closed box rests on one of its six faces. Of all such cannisters that could be used, what is the radius, in inches, of the one that has maximum volume ？（）

A．3

B．4

C．5

D．6

E．8

简述矩形试样的平行长度加工的尺寸要求。