1.   They cover the pit with tin sheets, cover the tin with dirt and light the wood.

2.   To accommodate the orchestra, the pit was covered with a platform and the first few rows of audience seats were removed.

3.   An inflatable tent will cover the pit, and the few experts allowed in will enter through an air lock, like on a space ship.

4.   Several such pits have been covered.

5.   They have to cover the pit at the bottom of the pillars to prevent them from becoming mosquito breeding grounds.