Our body clocks regulate our sleep-wake cycle.

I have two case clocks in my living room.

Chemical clocks are used to measure time in chemical reactions.

I have two clock radios in my bedroom.

The clock-watchers arrived late to the meeting.

The office is full of clock watchers.

I saw many flower clocks in the park.

Pendulum clocks are fascinating timekeeping devices.

The segmentation clocks control the development of the embryo.

The shot clocks in the basketball game were malfunctioning.