【判断题】水质监测中UV254测定结果的单位是有机物浓度,mg/L。
【单选题】Spare parts
A.
The spare parts are purchased
B.
The spare parts are made in the factory
C.
There is a spare parts store in the factory.
【简答题】阅读理解 Are you looking for something fun and would you like to help other people in your spare time?Then join us to be a volunteer(志愿者). We are a non-profit organization(非盈利性组织). We have volunteer jobs ...
【单选题】对话理解 听力原文:W: Since I have some spare cash in my account, I would like to open a time deposit account here. Can you give me some information please? M: With pleasure. We have many kinds of time deposit...
A.
Customs officer and travelers.
B.
Employer and employee.
D.
Bank clerk and customer.
【判断题】蓄电池是一种化学电池,其基本组成为正极板、负极板、隔板和电解质。
【简答题】化学电池基本组成是____、_____、______和_______。
【单选题】将氢气、甲烷、乙醇等物质在氧气中燃烧时的化学能直接转化为电能的装置叫燃料电池.燃料电池的基本组成为电极、电解质、燃料和氧化剂.此种电池能量利用率可高达80%,产物污染也少.下列有关燃料电池的说法错误的是 [ ]
A.
上述燃料电池的负极反应材料是氢气、甲烷、乙醇等物质
B.
氢氧燃料电池常用于航天飞行器,原因之一是该电池的产物为水,经过处理之后可供宇航员使用
C.
乙醇燃料电池的电解质常用KOH,该电池的负极反应为:C 2 H 5 OH-12e - ===2CO 2 ↑+3H 2 O
D.
甲烷燃料电池的正极反应可以为:O 2 +2H 2 O+4e - ===4OH -
【单选题】将氢气、甲烷、乙醇等物质在氧气中燃烧时的化学能直接转化为电能的装置叫燃料电池。燃料电池的基本组成为电极、电解质、燃料和氧化剂。此种电池能量利用率可高达80%(一般柴油发电机只有40%左右),产物污染也少。下列有关燃料电池的说法错误的是
A.
上述燃料电池的负极反应材料是氢气、甲烷、乙醇等物质
B.
氢氧燃料电池常用于航天飞行器,原因之一是该电池的产物为水,经过处理之后可供宇航员使用
C.
乙醇燃料电池的电解质常用KOH,该电池的负极反应为:C 2 H 5 OH-12e - =2CO 2 ↑+3H 2 O
D.
甲烷燃料电池的正极反应为O 2 +2H 2 O+4e - =4OH -
【简答题】They spend all their spare time, _________ their spare money, on their experiments. A:as soon as B:as well as C:as long as D:as much as