Which step displays a listing of all the data sets in the WORK library?
A. proc contents lib=WORK run;
B. proc contents lib=WORK.all;run;
C. proc contents data=WORK._all_; run;
D. proc contents data=WORK _ALL_; run;
Answer: C
注解：在PROC CONTENTS statement中，libref._ALL_用于显示libref这一SAS library下所有data set的信息。D缺了个“.”，如果libref是work的话，可以省略work，即data = _all_。