下列算式中,积为负数的是( )
A:0×(﹣5)
B:4×(﹣0.5)×(﹣10)
C:(﹣1.5)×(﹣2)
D:(﹣2)×(﹣15)×(﹣23)
“碧玉妆成一树高,万条垂下绿丝绦”能发育成万千枝条及其绿叶的结构是( )
解关于x的方程:log2x+14-log12x+2=3+log2x+6
- How long does it take to get to the airport?
- Forty minutes. But it's foggy today. I'm not sure _________ the highway will be closed soon. Let's set off earlier.
如图,已知AB、CD、EF都与BD垂直,垂足分别是B、D、F,且AB=1,CD=3,那么EF的长是( )