题目

Should e­cigarettes (electronic cigarettes) be a new choice for the smokers trying to get rid of the habit? Reactions from Americans are mixed.More than half of the people questioned in a survey think e­cigarettes should be controlled by the US Food and Drug Administration，but 47 percent believe the e­cigarettes should be available to the smokers who want to quit. “In the hunt for a safer cigarette，e­cigarettes are becoming a popular choice among those either trying to quit or looking to replace standard tobacco smoke with an alternative that manufacturers claim to be safer，在△ABC中，角A，B，C所对的边分别为，b，c，若，b=2，sinB+cosB=，则角A的大小为    （   ）A． B． C． D．