A:rise
B:arising
C:raising
D:rising
—I _______to the cinema yesterday. —It's a pity. You didn't invite me.
如果等差数列an中,a3+a4+a5=12,那么a1+a2+…+a7=( )
对于进行有性生殖的生物体来说,维持每种生物前后代体细胞染色体数目恒定的生理作用是( )