结肠癌经淋巴道转移最先至（）.
A.结肠旁淋巴结
B.腹股沟淋巴结
C.腹主动脉旁淋巴结
D.左锁骨上淋巴结
E.胸腔纵隔淋巴结
参考答案：A
—Tell the children _____ unhealthy food.
—OK, I will. I know it's bad for their health. [ ]
A. not to eat
B. to eat
C. eat
下列物质中，在一定条件下能够发生水解反应，且水解的最终产物只有一种的是 [ ]
A．蚕丝
B．淀粉
C．豆油
D．乙烯
