2、提取以指定字符结尾的行 > a <- c("abc","axy","123","axy","mnp")> b <- c("dse","bcd","ee4","sdb","345")> c <- c("mcy","873","345","egs","dfe")> dat <-data.frame(a, b, c)>dat## 测试数据框a b c1abc dse mcy2axy bcd8733123ee43454axy sdb egs5mnp345d...