题目

________ going into the classroom, I turned on the light because it was very dark.A.Upon B.FromC.During D.For 答案：【答案】A【解析】考查介词辨析。句意：一进入教室，我就打开灯，因为里面很黑。A. Upon一……就……；B. From从……起；C. During在……的期间；D. for为了。根据I turned on the light because it was very dark可推知，是一进入教室就开灯。故选A。3个5角合起来是1元5角。（________）