He was afraid ______ making friends with anyone.[ ]
A. of
B. to
C. in
D. for
答案:A
葡萄糖进入红细胞属于[ ]
A.主动运输
B.协助扩散
C.自由扩散
D.胞吞
不属于被覆黏膜的是 ()
A.牙龈
B.颊黏膜
C.唇黏膜
D.硬腭
E.舌背黏膜