DENVER — A trauma center reported a sharp decrease in backover injuries among small children after a federal law made backup cameras in cars mandatory, according to a presentation at the AAP National ...

Guest: Caroline Fraser is the author of Prairie Fires: The American Dreams of Laura Ingalls Wilder, which won the Pulitzer Prize as well as the National Book Critics Circle Award, the Heartland Prize, ...

ACSL美国计算机科学思维挑战活动，原名美国计算机科学联赛，最初成立于1978年，起源于美国硅谷，最初名为the Rhode Island Computer Science League，后为the New England Computer Science League。随着越来越多全世界的参赛者加入竞赛，最终命名为了American Computer Science League。