We have been told that under no circumstances _______ the telephone in the office for personal affairs. [ ]

He has ______ for some years, but his _____ still makes us very sad now.

If there are ______ trees, the air in our city will be _______ cleaner.

Lily __________ the space museum after school yesterday.

er I met her，________ was fairly often, she greeted me with a sweet smile.