自2010年至今的四级考试中， 共出现过 次
自2010年至今的六级考试中， 共出现过 次
N-UNCOUNT 车流;交通 Traffic refers to all the vehicles that are moving along the roads in a particular area.
There was heavy traffic on the roads...
Traffic was unusually light for that time of day.
N-UNCOUNT (海上、铁路或空中的)交通，通行;(客、货)运输量 Traffic refers to the movement of ships, trains, or aircraft between one place and another. Traffic also refers to the people and goods that are being transported.
Air traffic had returned to normal...
The railways will carry a far higher proportion of freight traffic...
N-UNCOUNT (毒品、赃物等的)非法买卖，非法交易 Traffic in something such as drugs or stolen goods is an illegal trade in them.
Traffic in illicit drugs was now worth some 500 thousand million dollars a year.
如今每年非法毒品的交易值约在 5,000 亿美元。
VERB 非法买卖(毒品、赃物等) Someone who traffics in something such as drugs or stolen goods buys and sells them even though it is illegal to do so.
The president said illegal drugs are hurting the entire world and anyone who traffics in them should be brought to justice.