Mick, the ice climber, interrupted them before Dean could think up a proper reply.
He hung up before Fred had to think up a response.
What I thought was that you were prepared to use your program to calculate some difficulty indices that people might think up.
But she had to remind the others every now and then in case the boredom made them think up dangerous pranks.
Sit down and think up a short list of all of the above.