Even on the most careful prepared trip, problems will sometimes happen.
=> carefully
The phrase "keeps sellers on their toes" in the passage mostly means "______".
Tom: "___________________ " Mike: "I won't say no!"
The examination was not very difficult, but it was_____________________ long.
Standing on the tip of the cape,____________________ .
_______ has been a topic of continual geological research.
__________ John Kennedy was elected president, he was the youngest American President ever.
Only one of our gifted students______to participate in the final competition.
We must push the piano to the corner of the hall to_____________________ our party tonight.
The pool should not be made so deep______small children can be safe there.
The boat was sailing north when a terrible storm_____________ .