用恰当的单词填空完成表格。
College students volunteer in the US
In ____
They ____books to the sick people or listen to their problems.
In old people's homes
They help to clean up or go ____.
In the ____clubs
They remember the problems of boys and girls
如图,路灯点O到地面的垂直距离为线段OP的长.小明站在路灯下点A处,AP=4米,他的身高AB为1.6米,同学们测得他在该路灯下的影长AC为2米,路灯到地面的距离____米.
下列关于分子的叙述中不正确的是( )
已知lga+lgb=0,函数f(x)=ax与函数g(x)=﹣logbx的图象可能是( )