A.dangerous
B.risky
C.safe
D.perilous

A.safe and sound
B.in reality
C.under control
D.under pressure

A.inapplicable
B.avoidable
C.unrecognizable
D.invisible

A.with
B.to
C.off
D.by

A.game
B.data
C.information
D.program

A.reaction
B.react
C.reactivate
D.reactivity

A.play
B.touch
C.press
D.punch

A.playing
B.surfing
C.appearing
D.watching

A.renewed
B.opened
C.restarted
D.upgraded

A.store
B.get
C.have
D.make