下列事实不能证明HNO2是弱酸的是( ) A.常温下NaNO2溶液的pH>7 B

题型:选择题

问题:

下列事实不能证明HNO2是弱酸的是(  )

A.常温下NaNO2溶液的pH>7

B.用HNO2溶液做导电实验,灯泡很暗

C.0.1mol•L-1的HNO2溶液的pH=2

D.pH=3的HNO2溶液稀释至100倍后,3<pH<5

考点:弱电解质的电离
题型:选择题

Life in the future will be different from life today. Between then and now many changes will happen. But what will the changes be?

The population is growing fast. There will be many people in the world and most of them will live longer than people live now.

Computers will be much smaller and more useful,and there will be at least one in every home. And computer studies will be one of the important subjects in schools then. People will work fewer hours than they do now and they will have more free time for sports,watching TV and traveling. Traveling will be much cheaper and easier. And many more people will go to other countries for holidays.

There will be changes in our food,too. More land will be used for building new towns and houses for all the people. Then there will be less room for cows and sheep,so meat will be more expensive. Maybe no one will eat it every day. Instead,they will eat more fruits and vegetables. Maybe people will be healthier. Work in the future will be different,too. Robots will do dangerous and hard work. Because of this,many people will not have enough work to do. This will be a problem.

小题1:In the future there will be ______.

A.much more fruit

B.fewer people

C.less vegetables

D.less people小题2:Every family will have at least a ______ in the future.

A.robot

B.cow

C.TV set

D.computer小题3:In the future people don't have to ______.

A.work long hours

B.work fast

C.walk on foot

D.eat meat小题4:People may not eat ______ as much as they do today.

A.fruit

B.fish

C.meat

D.rice小题5:One big problem in the future is that ______.

A.many people don't have to work

B.many people will not be able to find work

C.people have to work fast

D.all the work will be done by robots

题型:选择题

某历史研究性学习小组开展研究性学习活动,收集整理了以下材料:

(1)“一五计划”重工业成就统计表(2)大跃进时期流行的口号(3)当地近30年来城市面貌变化图片(4)中共八大以采党的会议文献 你认为该研究性学习小组活动主题最贴切的是

A.新民主主义的理论与实践

B.社会主义建设道路探索

C.中国社会主要矛盾的演变

D.建国以来重工业发展史

题型:选择题

预应力混凝土构件与普通混凝土构件特点有何不同

题型:选择题

特种设备事故发生后,事故发生单位应当立即启动事故应急预案,组织抢救,防止事故扩大,减少人员伤亡和财产损失,并及时向事故( )特种设备安全监督管理部门和有关部门报告。

A.国家安全监督管理总局
B.事故发生地县以上
C.事故发生地县级
D.生产单位安全科

题型:选择题

表示某特定时间内,被观察的总人口中某病新、旧病例所占的比值

A.病死率
B.发病率
C.死亡率
D.患病率
E.治愈率

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