单项选择题
A.readLines（/Documents/expenses/november.csv）B.read.csv（“/Documents/expenses/november.csv”）C.read.csv（/Documents/expenses/november.csv）D.read.csv（“november.csv”，folder =“Documents/expenses”，type =“csv”）
A.myarray[3]B.myarray[，3]C.myarray（row =“third”）D.myarray[3，]
A.mean（“ratings”）B.AVER（“rating”）C.mean（ratings）D.average[ratings]