题目

Barry White, Jt., a fifth grade English teacher at Ashley Park PreK-8 School, has a personalized handshake as greetings with every one of his students every day.The students know that when they ________ the school gate we do our ‘good mornings,’ and then it’s time to ________ ” White told ABC News of his enthusiastic ________. “I’m always pumped up ________ . we start doing the moves, which brings them ________ and cheers them up for a high-energy ________.”Each handshake is different, using custom moves inspired by the student’s personality.“I started with one simple handsha若表示的区间长度，函数的值域区间长度为，则实数的值是（    ） A．4                  B．2               C．               D．1