皮皮学，免费搜题
登录
搜题
【简答题】
________ so many people in the United States been out of work as today. A. More than ever before B. In the past, there have never C. Never before have D. Formerly, there never were A. More than ever before B. In the past, there have never C. Never before have D. A. More than ever before B. In the past, there have never C. Never before have D. Formerly, there never were
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】在A1中输入“XYZ”，B1中输入数据100，C1中输入公式“IF(AND(A1=“XYZ”，B1＜100)，B1+10，B1-10)”，则C2中结果为______。
A.
90
B.
B1-10
C.
110
D.
B1+10
【单选题】20世纪，爱因斯坦由于“光电效应”的发现而获得诺贝尔物理学奖，那么爱因斯坦是通过引入以下哪个物理概念而完美解释光电效应的呢？
A.
光量子
B.
光波
C.
光粒子
D.
电磁波
【简答题】20 世纪,爱因斯坦由于 “ 光电效应 ” 的发现而获得诺贝尔物理学奖,那么爱因斯坦是通过引入以下哪个物理概念而完美解释光电效应的呢?