(A)→(P), (Q) When two circles are intersecting, they have a common normal and common tangent. (B)→(P), (Q) Two mutually external circles have a common normal and the common tangents. (C)→(Q), (R) When one circle lies inside of the other, then they have a common normal but they do not have common tangents. (D)→(Q), (R) Two branches of a hyperbola have a common normal but they do not have common tangents.