A:putting back
B:having put back
C:to put back
D:will put back
酒精的热值比干木材大,下列说法中正确的是( )
已知函数f(x)=15x5+x3+4x(x∈R),数列{an}是等差数列,a3>0,f(a1)+f(a3)+f(a5)的值( )