在上皮细胞最靠近管腔的连接是（）。
A.紧密连接
B.粘合带
C.桥粒
D.半桥粒
E.间隙连接
参考答案：A
用括号内所给词的适当形式填空。
1. She was _____ (embarrass) when they asked her age.
2. My mother cried because of the sad _____ (end) of the movie.
3. We feel _____ (exhaust) after an hour's walk.
4. My cousin will get _____ (marry) next moth.
5. His arguments sound _____ (convince). Everyone believes him.
下列物质中所含碳原子数最接近阿伏伽德罗常数的是（ ）
A．1 mol碳单质
B．0.5L 1mol/L的醋酸溶液中CH3COOH、CH3COO-之和
C．标准状况下，12g碳单质
D．标准状况下，22.4L CO2气体
