建筑详图的索引标志是以一个直径为（）毫米的圆圈来表示。在圆圈内需表示出该详图的编号及详图所在图纸的编号。
参考答案：8～0
Miss Zhao is very helpful. She often helps us ____we are in trouble. [ ]
A. whether
B. although
C. whenever
D. however
—A number of children ______ standing outside the office when I got there.
—The number of the children______ 16. [ ]
A. is; are
B. is; is
C. are; is
D. are; are
