分泌胃泌素的细胞是
A．黏液细胞B．壁细胞C．胃窦部G细胞D．主细胞E．胃上皮细胞
参考答案：C
—Why! Where’s my mobile phone? Maybe I left it on the plane.
—My goodness! You things behind.
A．haven’t left
B．didn’t leave
C．had never left
D．never leave
按细胞结构可将微生物分为哪几类？
