-Is it polite to speak or laugh loudly ? -No, I don't think so.
--I hear this kind of CD-ROM is very popular.--Let’s buy one before it ____________.
This problem is ______ difficult __________.
_____ hard work it is! But _____ fun it is to finish walking the trail.
The life we were used to ________ greatly since 2002
Your shoes under the bed _________. Put them in the sun, please.