1.   And the care taken in constructing and sealing the pit may suggest that the leaders thought they could get away with some murders early on.

2.   It is due to close by the end of October, and the few workers left are busy salvaging equipment, dismantling machinery and helping seal the pits.

3.   It is due to close by the end of October, and the few workers left are busy salvaging equipment, dismantling machinery, and helping seal the pits.

4.   Some burial pits were sealed.

5.   The plutonium pits are sealed inside a stainless-steel shell.