下列各式计算正确的是( )
A:2a+3b=5ab
B:12x-20x=-8
C:6ab-ab=5ab
D:5+a=5a
根据句意及词首字母或汉语提示,补全单词。(1)Don't talk l____ in the classroom. It's impolite(不礼貌的).(2)The movie is so boring. I can't s____ it.(3)The clothes shop is on sale. This shirt is very c____ .(4)Yesterday, Kate studied for the English t____ .(5)Please ____ (记住)to turn off the lights.
— What can ____ (he, she) do?
— She can fly.
2006年我国政府工作报告提出了建设节约型社会的四项措施:
A.原料的综合利用 B.开发新能源 C.降低能源消耗 D.废物回收利用
下列项目分别落实了哪项措施,请将该项措施的序号填入括号内:
①研制开发耗电量少的节能灯____
②在海水淡化厂,提取多种物质____
③垃圾分类回收和建立垃圾发电站____
④回收废旧电池,进行再利用____
⑤种植油料作物,开发生物柴油____
⑥提高火电厂原煤的利用率____.
生活处处有化学.