蓄电池每年应以实际负荷做一次核对性放电实验,放出额定容量的()。
A.10%—20%
B.20%—30%
C.30%—40%
D.40%—50%
参考答案:C
Your vessel is equipped with totally enclosed lifeboats. Which statement is true when the boat is enveloped in flames?().
A.The ventilators will automatically close by the action of fusible links
B.The motor takes its air supply from outside the lifeboat to prevent asphyxiation of the crew
C. A water spray system to cool the outside of the boat is operated by a high-volume manual pump
D.An air tank will provide about ten minutes of air for the survivors and the engine
根据Fibonacci数列公式: [*] 计算并输出[*]前20项之和。