题目

阅读理解An American teacher who helped make college education accessible to low-income,immigrant (移民), first-generation American,and refugee (难民) pupils has won the $1 million GlobalTeacher Prize. Keishia Thorpe, an English teacher in Maryland, wasselected from more than 8,000 teachers in 121countries.As a young girl from the circumstances that Icome from, I would never have thought something like this would ever happen tome. I'm speechless, I'm overjoyed, I'm amazed. This is just an extraordinaryachievement for me, Ms. Thorpe said.Ms. Thorpe teaches English to 12th-graders at the下列说法正确的是__________A．电子束通过铝箔时的衍射现象证实了电子也具有波动性B．氢原子的核外电子由较高能级跃迁到较低能级时，电子的动能增大，电势能减小C．对于任何一种金属都存在一个“极限波长”，入射光的波长必须小于此波长，才能产生光电效应D．光电子的最大初动能与入射光的强度有关