我国面积最大的省级行政区是[ ]
A．西藏自治区
B．新疆维吾尔自治区
C．北京
D．河南省
答案：B
The artist made up his mind to devote all he could ______ his English before going abroad. [ ]
A. improve
B. to improve
C. to improving
D. improving
诊断新生儿甲状腺功能减退的最佳依据是（）
A.患儿少吃、少动、低体温
B.黄疸时间延长
C.腹胀、便秘
D.骨龄落后
E.新生儿筛查
