David Beckham decided to __________ playing football match forever because he is not energetic(精力充沛的)enough.
人们常给移栽的大树打针输液,输入的营养液是( )
在等差数列{an}中,a1+a9=10,则a5的值为( )
I won't go to his party, . Because I have to prepare for my math test.