已知两圆的半径分别为2和4,圆心距为6,那么这两圆的位置关系为[ ]
A. 外离
B. 相交
C. 内含
D. 外切
答案:D
下列腧穴中,常用于治疗呃逆症的是()
A.睛明
B.攒竹
C.承泣
D.四白
E.印堂
After the break, the lecturer went on to talk ______ about the new academic concept. [ ]
A. at length
B. in all
C. in turn
D. at most