▪ frantic , frenetic , heightened , increased , intense
The scene was one of frenetic ~.
▪ criminal , illegal , subversive , suspicious , terrorist
His income was derived from criminal ~.
▪ class ( esp. AmE ), classroom , group
▪ after-school , extra-curricular , leisure , leisure-time , outdoor , recreational , social
Shopping is now a leisure ~.
▪ mental , physical , sexual
They had engaged in sexual ~ in the past three months.
▪ aerobic , strenuous
▪ business , commercial , cultural , economic , industrial , intellectual , political , scientific
▪ government , military , police , union
▪ electrical , seismic , volcanic
The islands were formed by volcanic ~.
… OF ACTIVITY
▪ burst , flurry
There was a flurry of ~ as the movie star appeared on the balcony.
Newspapers report a higher level of ~ in the foreign-exchange markets.
VERB + ACTIVITY
▪ conduct , do , perform
Here's an ~ you can do with mixed-ability classes.
▪ be involved in , engage in , participate in , take part in , undertake
We suspect he may be involved in illegal activities.
Teachers here are not allowed to engage in any political ~.
▪ stop , suspend , terminate
The party's activities have been suspended.
It will only be possible to stimulate business ~ with an injection of public funds.
▪ curb , inhibit
▪ coordinate , regulate
▪ measure , monitor
▪ bustle with , buzz with
The room was buzzing with ~.
▪ a hive of ~ (= a very busy place)
The classroom was a hive of ~ as the children prepared for the concert.
▪ a sign of ~
Police watched the house all day, but there was no sign of ~.