《中图法》规定类号中当数字符号超过（）位数时，每隔三位数用小圆点“.”加以分隔。
参考答案：三
He decided ________ swimming because it was so hot. [ ]
A. go
B. to go
C. going
D. goes
Kernig征检查时阳性表现为
A．浮肋B．肋脊角C．胸骨角D．腹上角E．肩胛下区
