A:To be
B:For
C:A
D:With
如图,已知菱形ABCD,AB=5,对角线BD=8,作AE⊥BC于点E,CF⊥AD于点F,连接EF,求EF的长.
下列反应中,生成物的总能量大于反应物的总能量的是( )
设集合A={x|1<x<4},集合B={x|(x﹣3)(x+1)<0},则A∩B=( )
Stop cutting trees, _______ the earth will become worse and worse.