波士顿爆炸案使美国安保级别提升波士顿马拉松爆炸案发生之后，美国国内从世贸中心、时报广场，到白宫及各类体育场馆均提高了安保级别，警方增派了重点场所的巡逻警力，并派出反恐小分队参与安保工作。 From the World Trade Center and Times Square in New York to the White House and sports venues across the country, police patrolled in packs and deployed counterterrorism teams Monday as security was stepped up after explosions at the Boston Marathon. Worries also reverberated（使回响，使反射） across the Atlantic, where an already robust security operation was being beefed up for Wednesday's ceremonial funeral for former Prime Minister Margaret Thatcher. The event at St. Paul's Cathedral, to be attended by Queen Elizabeth II and other dignitaries, calls for a procession through the streets of London, with Thatcher's flag-draped coffin carried on a horse-drawn carriage. British police were also reviewing security plans for Sunday's London Marathon — the next major international race — because of the bombs that killed three people and injured more than 140 in Boston. Across the U.S., security was tightened at landmarks, government buildings, transit hubs and sporting events. Law enforcement agencies also urged the public via Twitter and Facebook to report suspicious activity to the police. In New York, authorities deployed so-called critical response teams— highly visible patrol units that move in packs with lights and sirens, — along with more than 1,000 counterterrorism officers. Highly trafficked areas like the Empire State building, Rockefeller Center, St. Patrick's Cathedral, the United Nations and the World Trade Center site were being especially monitored. Mayor Michael Bloomberg said the police department was fully prepared to protect the...
