致龋作用最强的碳水化合物是
A.乳糖
B.蔗糖
C.麦芽糖
D.淀粉
E.果糖
参考答案:B
Thanks to the application of new farming methods,output is now six times _____it was before 2000.
A.that
B.what
C.which
D.how
胃肠道可发生类癌的部位为()
A.十二指肠
B.空肠
C.阑尾
D.胃
E.大肠