clear zone zone

the alternative occurrence of fractured zone and non-fractured zone

trade-wind zone [= zone of trade wind]

zone by zone upgoing

1st grade clean operating room

2D clean up

8-bit clean

a clean and efficient government

a clean and honest administration

a clean sheet

a new broom sweeps clean

Absolution Clean Technique

acid clean fracturing fluid

agricultural clean production

Air clean index

air seal type clean draft chamber

Anti-static and clean room clothing

Aqua Clean ACF32

banker’s clean bill