21.  A better plan would be to launch from Earth on a trajectory optimized for transfer to Mars.

22.  A big crowd started to gather as Greg got on a real head of steam.

23.  A big reason for the Decrease in smoking is the ban on cigarette advertising.

24.  A big truck had turned over on its side, and it was blocking the road.

25.  A big white heron gallops out of the creek on his gawky orange legs and gobbles it up.

26.  A bipartisan tax bill will have to bridge big differences between the parties on capital gains tax cuts.

27.  A black flotilla of clouds rose towering over the mountains and advanced on the house.

28.  A black knight appeared, as though out of profound shadow, on the surface of the ultimately narrow board.

29.  A black widow spider has a distinctive red hourglass Marking on its stomach.

30.  A black, felt bowler sits on his head, tilted slightly forward at a rakish angle.