站内线路的道岔及与()相衔接的道岔,由车站负责管理。
A、其他单位所管路线
B、专用线
C、段管线
D、岔线
参考答案:A
下列生活事例中,主要属于化学变化的是( )
A.节日燃放烟花
B.夏日冰棍融化
C.美酒开瓶飘香
D.彩纸剪成窗花
A certain alloy contains only lead, copper, and tin. How many pounds of tin are contained in 56 pounds of the alloy ?()
(1)By weight the alloy is lead and copper.
(2)By weight the alloy contains 6 parts lead and 5 parts copper
A.条件(1)充分,但条件(2)不充分.
B.条件(2)充分,但条件(1)不充分.
C.条件(1)和(2)单独都不充分,但条件(1)和条件(2)联合起来充分.
D.条件(1)充分,条件(2)也充分.
E.条件(1)和条件(2)单独都不充分,条件(1)和条件(2)联合起来也不充分.