分泌内因子的细胞是（）
A.主细胞
B.壁细胞
C.黏液细胞
D.胃幽门黏膜G细胞
E.胃黏膜表面上皮细胞
参考答案：B
A great many teenagers became ________ playing computer games,wasting their precious time. [ ]
A. accustomed to
B. addicted to
C. used to
D. due to
有关叶绿素的叙述，正确的是（）
A.叶绿素都在叶绿体内合成
B.叶绿素在酸性环境中保持稳定
C.纤维素酶不能催化叶绿素分解
D.叶绿素比叶黄素更易溶于层析液
