Maybe you have been to many interesting places, but nowhere else in China ____ such a beautiful place.

Exactly ____they did when at last they reached the sea remains a complete mystery.

In our class, 85% of the students take the bus to school. So _______ students in our class get to school by bus.

What do you often do _____________ classes to relax?–Listen to music or walk around the school.A．over

Unit Six is ________ most difficult lesson, but it isn’t ________ most difficult one in this book.