It took the police a long time to find some evidence. The new evidence led to _______.

A．the robber having caught

B．catch the robber

C．the robber being caught

D．the robber to be caught

31. —How long_________each other before they_________married?

—For about a year.

A．have they known, get

B．did they know, were going to get

C．do they know, are going to get

D．had they known, got