A: borrow, lend
B: keep, lend
C:lend, borrow
D:keep, borrow
古诗文默写。
用你所学的生物知识判断,下列说法正确的是( )
My students,________you have a heart loving life,you always can find things that would make you happy each day.
已知变量x,y,满足2x-y≤0x-2y+3≥0x≥0,则z=log4(2x+y+4)的最大值为____