check；    without；     private；     indoors；     outside；     works of art；

（1）I like being　　， near beautiful lakes and hills．

（2）﹣﹣﹣ What time is it？

﹣﹣﹣ I have no idea． But just a minute， I will　　 it for you．

（3）This is my father's own　　 chair． No one else is allowed to use it．

（4）There are lots of　　 in the Palace Museum． Don't miss them!

（5）A serious study of physics is impossible　　 some knowledge of maths．