----- Believe it or not, my sister and I are twins.
----Oh, you must have had the case ________ you were taken for your sister.

With the rapid development of the city, he can hardly find the place __ he used to play with his childhood friends.

The science of computer,____ rapid progress has been made, is the most important of all.

Whenever his mother spoke to him, ____ was fairly often, he would talk on and on without giving her a chance to speak.

Charles Dickens, a famous 19^th- century writer, wrote many popular novels, __________ Oliver Twist is a good example.

_____was expected, he broke his promise once more, ______left his friends down.

These articles are written in simple language, _____ makes it easy to read.

It is said that this is the biggest lab ________ they have ever built in their school.

The days are gone ________ we could leave our door unlocked at night.

People _______ the dead person was related would make paper-cut offerings on special days.