To minimize contamination by the overlying water, the jars remained covered until they touched the lake bottom and the sediment was collected.
(the jars; remained; covered; T:until they touched the lake bottom and the sediment was collected) (the jars; covered; T:until they touched the lake bottom and the sediment was collected) (they; touched; the lake bottom) (the sediment; was collected; )
the jars the jars they the sediment
remained covered touched was collected
covered T:until they touched the lake bottom and the sediment was collected
T:until they touched the lake bottom and the sediment was collected
the lake bottom