【判断题】Zm的每个元素是可逆元或者是零因子。()
【判断题】对于经常处于低温状态的结构,钢材容易发生冷脆断裂,特别是焊接结构更严重,因而要求钢材具有良好的塑性和低温冲击韧性。
【判断题】区段人工解锁按钮盘的作用是用于人工解锁。
【单选题】电气集中联锁系统中,用于排列进路的设备是?
【单选题】Which of the following statements CANNOT be inferred from the passage?
A.
People are increasingly able to see the damage they are doing to the ocean,but to solve th e problems,they will meet with great difficulties.
B.
By the middle of the century,the edible fish will have harmful effects on human health.
C.
Earth is not exactly named,because the ocean covers almost three quarters of the planet.
D.
High temperature can damage corals and encourage organisms to migrate towards the poles in search of cooler waters.
【判断题】人工解锁按钮盘主要是用于对进路中故障区段的解锁。
【单选题】下列关于区段人工解锁按钮盘作用说明正确的是 。
A.
设在离控制台一定距离的室内墙面上,是控制台的主要设备之一;
B.
当轨道电路因故障不能正常解锁时,用它办理故障解锁;
D.
在用取消进路办法不能关闭信号时,用它也不能关闭信号。