用热水烫番茄，很容易从番茄表面撕下一层“皮”，这层“皮”属于（ ）
A．营养组织
B．输导组织
C．保护组织
D．分生组织
答案：C
—Look, what an old palace! It looks so great!
—Yeah, it _____ nearly 800 years ago. [ ]
A. was building
B. was built
C. has built
D. is built
120阀与103阀的零件完全不能通用互换。
