有这样一幅对联:电荒、油荒、煤慌,慌慌心惊;产能、供能、用能,环环节约。横批是:科学发展。这幅对联给我们的启示是( )
①我国的能源问题已得到解决 ②要牢固树立科学发展观
③节约能源要从点滴做起 ④限制工业发展是避免能源危机的唯一途径
A:①②
B:②③
C:③④
D:②④
Hi,I am Susan. I am from the USA. But now I'm studying in China. I'm going to do many things during(在……期间) the winter holiday. First,I'm going to finish my homework. Then I'm going to take a trip. I'm going to go to Beijing. It is the capital(首都) of China. It will be snowy in Beijing. There will be snow everywhere. So I'm going to make a snowman. My parents will come to China and go with me. We are going to fly to Beijing. We are going to have a nice trip.
观察下列等式:解答下面的问题:21+22+23+24+25+26+…+22015的末位数字是____ .
某学习小组6人的一次数学测验成绩分别为50分,100分,60分,70分,80分,60分,则这次成绩的中位数、众数分别为 ( )
在3Fe+2O2═Fe3O4反应中, ____ 份质量的铁跟 ____ 份质量的氧气反应,生成 ____ 份质量的四氧化三铁.