---Tell me something about your adventure in the rainforest, please.---We lost our way in the forest and ___ made matters worse was ___ night began to fall.

Water, which seems to be so simple and common, is ______ makes life possible.

One advantage of owing your own car is ________ you can go anywhere at any time you like.

He kept yawning in class this morning. That is _____ he stayed up late doing his homework last night.

—Don't you think it necessary that he ________ to Miami but to New York?—I agree, but the problem is ________ he has refused to.