一种新型燃料电池,是用两根金属铂做电极插入KOH溶液中,然后向两极上分别通入CH3OH和O2,下解说法不正确的是 A.通入CH3OH的电极为负极
设集合. (1)若,求实数的值; (2)若,求实数的取值范围.
合理利用和保护自然资源的正确态度是( ) A.地大物博,大量消耗 B.控制人口是提高人均占有量的唯一途径 C.禁止使用非可再生资源,大量使
关于x的方程的两实数根互为倒数,那么m的值为 ( ) A. B.- C.2 D.-2
It is a good quality for a person to keep _______ when facing threats (威胁). A. quiet B. calm C. still D
丙烷的分子结构可简写成键线式结构,有机物A的键线式结构为,有机物B与等物质的量的H2发生加成反应可得到有机物A.下列有关说法错误的是 A.有机
(1)设ξ—B(n,p)且Eξ=2.4,Dξ=1.44,试求n、p的值.(2)在某地举办的射击比赛中,规定每位射手射击10次,每次一发,记分的规则为:击中目标一次得3分
I failed again in the exam and only then______ how much time I had wasted. A.I realized B. I had realized C. did I realize D. had I realized