Our English teacher told us to find out ____the differences between American English and British English lie.
The two dresses are very nice. I can’t decide _________。
Sixteen-year-olds should _________their ears pierced.
His grandparents used to ________ a walk after dinner, but now they are used to ________ a walk after breakfast.
My sister was ________out at night.
______ is necessary _______ us ________learn English well.