Across North China _____ in the world, namely the Great Wall.
[ ]
A. the longest wall runs B. runs the longest wall C. does run the longest wall D. does the longest wall run
参考答案:
This is an illness that may result in total blindness if .A..
This is an illness that may result in total blindness if .A.being left untreatedB.left untreatedC.not left treatingD.not having left untreated