21.   His return signaled the start of a lengthy rehabilitation effort to rebuild his bones and muscles as well as retune his nervous system to gravity.

22.   His shoulders looked hunched as he waited for the beep that signaled the start.

23.   Initially, it will be uncomfortably humid, but early next week, thunderstorms will erupt, signalling the start of the monsoon.

24.   It did not say the sport needs a salary cap, words that could signal the start of a potentially devastating labor war.

25.   It may also signal the start of tougher negotiations.

26.   It said the announcement signaled the start of a diversification of the astronaut corps, with educators at the head of the line.

27.   It may signal the start of phone wars under competition.

28.   It signals the start of a gradual shift toward alternative transit in the park.

29.   Minutes before sundown, Sylvia stood by as Sruli lit the family candles, an essential ritual that signals the start of Shabbos.

30.   My bedside alarm clock signaled the start of a new workday.