CHECKING WORD FORM

These beautiful old towns have remained relatively untouched by _______________. (tour)

Plants are the main source of _______________ oxygen. (atmosphere)

There was a _______________ sunset last night. (spectacularly)

I hope the situation can be resolved _______________ . (peace)

The Grand Canyon is Arizona's biggest tourist _______________. (attract)

The station was closed for two hours because of a _______________ alert. (secure)

The passengers were _______________ up in a line to get boarding the airplane . (queue)

About 1,800 _______________ gardens worldwide in nearly 150 countries welcome more than 300 million visitors a year.

Costa Rica's national parks have made it a center for _______________ . (tour)

We were looking for the information desk to check our _______________ time. (depart)