The conflict had developed into a stage ______ the two countries were gathering big troops on the border.
Many students are ________ chatting online, which wastes them plenty of time.
The crowd ________ eastward, believing that they can find gold there.
Jack became seriously ill after ________ in polluted air for many years.
The new secretary is supposed to report to the manager as soon as she ________.
She ________ down beside me and soon fell a deep sleep.