把a、b、c、d 4块金属片浸入稀硫酸中，用导线两两相连组成原电池。若a、b相连时，a为负极；c、d相连时，d上产生大量气泡；a、c相连时，电流由c经导线流向a；b、d相连时，电子由d经导线流向b，则_刷题宝

题干

把a、b、c、d 4块金属片浸入稀硫酸中，用导线两两相连组成原电池。若a、b相连时，a为负极；c、d相连时，d上产生大量气泡；a、c相连时，电流由c经导线流向a；b、d相连时，电子由d经导线流向b，则此4种金属的活动性由强到弱的顺序为(　　)

A：a＞b＞c＞d

B：a＞c＞d＞

C：c＞a＞b＞d

D：b＞a＞c＞d

上一题下一题 0.0难度选择题更新时间:2018-03-25 04:01:43

答案(点此获取答案解析）

B

同类题1

图中共有____种水果。其中橘子有____个，占总数的____；菠萝有____个，占总数的____柠檬有____个，占总数的____。

同类题2

如图所示，斜面体M放置在水平地面上，位于斜面上的物块m受到沿斜面向上的推力F作用。设物块与斜面之间的摩擦力大小为F₁，斜面与地面之间的摩擦力大小为F₂。增大推力F，斜面体始终保持静止，下列判断正确的是（）

同类题3

如图是人体某项生命活动调节过程的示意图。据图判断，下列说法中正确的是

同类题4

根据短文内容的理解，选择一个最佳答案, 回答问题。

(A)

Li Hong is a middle school student. She is a Young Pioneer. Liu Ying is in her class. She is a Young Pioneer, too. They go to school at seven every day. They don't go by bus. They have most of their classes in the morning. On Tuesday afternoon, they have two hours of sports. School is over at four in the afternoon. They do their homework at home. Sometimes they like to play football or watch TV after school.

On Saturday afternoon they go to an old woman's house. She is about seventy. The two girls clean her room and carry water for her. They also buy things for her. They give the old woman a lot of help.

同类题5

一Who can help me?

—I can help you_________ it．

小学学科试题库

初中学科试题库

高中学科试题库