__________ caused the accident is still a complete mystery.

People try to save time by using their own cars, and this ________ creates further problems.

______ many people’s expectation, he was defeated in the first round

Many strange new means of transport have been developed in our century, the strangest of _____ being perhaps the hovercraft(气垫船).

. — Thank you for picking me up in thisremote area!— _____. I’m just going in the samedirection.