排除

exclude; eliminate; remove; rule out; preclude; omit; obviate; overcome; leave out; leave; off; banish; exclusion; clearance; omission; to the exclusion of

外界

outside; the outside; the outside world; external

干扰

interfere; interfere with; disturb; disrupt; jam; meddle; intervene; invade; mess up; hamper; throw a spanner in the works; interference; disturbance; disruption; jamming