【简答题】A.The signing is very necessary. B.The signing is just a reassurance. C.The signing is not very necessary. D.The signing is a way to monitor abuse.
【单选题】听力原文:W: I love the beach when the sand is fine and the water is just barely making waves. M: I prefer an angry sea. That makes me feel better whenever I'm sad. Q: What does the man like? (14)
【单选题】病人采用鼻导管吸氧时,氧流量为2L/min,此时氧浓度是
【单选题】2017年2月,中美科学家联合开发出一种新型结构的硫化锑基负极材料,使硫化锑基钠离子电池寿命几乎可媲美锂电池。关于钠离子电池与锂离子电池的异同,下列说法错误的是( )。
A.
二者工作原理类似,都是利用离子在正负极之间嵌脱过程实现充放电
B.
钠离子电池成本更低,因为钠盐原材料储量丰富,价格低廉
C.
与锂离子电池相比,钠离子电池可以使用低浓度电解液
D.
锂离子不与铝形成合金,负极可采用铝箔作为集流体
【单选题】听力原文:W: I love the beach when the sand is fine and the water is just barely making waves. M: I prefer an angry sea. That makes me feel much better whenever I'm not happy. What does the man like?
【判断题】锂离子电池的正极集流体材料使用的是铝箔,而负极使用的是铜箔。
【单选题】In a diesel engine, when the fuel is injected into the cylinder, .
A.
the piston is just coming upward from the bottom dead center
B.
the piston has moved about one-fifth of the way up
C.
the piston has moved most of the way up and almost reached the TDC
D.
the piston has just past the TDC