变化

The city has undergone/witnessed a marked change.

Prices vary with the seasons.

Things are changing fast. / The situation is changing rapidly.

change in both state and volume

variations in public opinion

change in social status

grateful/welcome change

change suddenly/abruptly

emotional shifts

change/variation in temperature

chemical/physical change

bring about/effect/entail a change; effect an alteration

adapt to changes

undergo changes

bring changes (to)

change tactics

change one's lifestyle