In America, if ________ friend has invited you to drop by anytime, it is ________ best to call before visiting to make sure it is convenient for him.
The seaside here draws a lot of tourists every summer. Warm sunshine and soft sands make __________ it is.
__________ parents say and do has a life-long effect on their children.
__________ matters most in learning English is enough practice.
Choosing the right dictionary depends on __________ you want to use it for.
Having checked the doors were closed, and ___ all the lights were off, the boy opened the door to his bedroom.