A:who; I think are
B:that; I think i
C:what; who I think i
D:who; that I think are
下列是显微镜的目镜和物镜的倍数,看到细胞数目最多的一台显微镜是( )
化学方程式a C2H2+b O2c H2O+d CO2配平后a、b、c、d数值为( )