1.A raw data file is listed below.
1---+----10---+----20---+---
son Frank 01/31/89
daughter June 12-25-87
brother Samuel 01/17/51
The following program is submitted using this file as input:
data work.family;
infile 'file-specification';
<insert INPUT statement here>
run;
Which INPUT statement correctly reads the values for the variable Birthdate as SAS
date values?
a. input relation $ first_name $ birthdate date9.;
b. input relation $ first_name $ birthdate mmddyy8.;
c. input relation $ first_name $ birthdate : date9.;
d. input relation $ first_name $ birthdate : mmddyy8.;

这个题的正确答案是D
我的疑问是 我觉得没必要加入colon modifier (:) 在这里 觉得b也是对的