May , is this the Hall of Ancient China ?   Yes . Look at these historical relics here , amazing !   Why are they all in glass boxes ?   For protection . Some relics will turn to dust if exposed to air .   So there isn't air in the glass boxes ?   No , there isn't . There is a vacuum in every box .   I wonder how old these things are . Thousands of years ?   Yeah , they all come from a very ancient time .   Hey , look at the tripod . I've seen it on TV . 