小儿喉腔最狭窄的部位是()。
A.环状软骨水平
B.声门裂
C.前庭裂
D.喉前庭
E.喉中间腔
参考答案:A
44. —Look!The boy is doing some washing.
—He is only eight years old, but he is very ________.
A.lonely
B.separate
C.responsible
D.independent
主要存在于水果中的单糖为()。
A.麦淀粉
B.果糖
C.乳糖
D.纤维素
E.果胶