Any way i got the answer the answer for the 4'th question is

.sas7dbat
for versions7,8 and 9 the file extension is .sas7bdat.
For the version 6 on UNIX it has the file extension .ssd01 
and on windows it has .sd2.

5. Proc datasets procedure and proc copy procedure where 
proc we can copy.

6. double options gives space between coumns

10. symput to store or assigna a value and symget to get a 
value.

3. We can create datsets from rawdata files.
manipulate the datasets, merging, appending,concatinatig,
all we can.

ans for 8'th one

by using where statement no need to read all the
observations in data step only we can read the mentioned
variable or observation

9th question ans 


ENDSAS; is used to terminate the SAS program.

1a) 9 ways to create macro variables 
1.into clause of proc sql
2.%local
3.%windows
4. %input
5.%let
6.%do 
7.call symput
8.
9.
2a)confidence limit means in statics procedure to get 
confidence limit means for certain degree to get statics to 
analyse the data
3a
4a).sas7dbat
5a)proc copy in= dataset out=output dataset;
select dataset;
run;
6a)double option is used in proc print procedure to leave a 
blank line between two consecutive rows in an listing 
output and does not show any effect on html output
7a)proc report produce summary tables with plenty options 
8a)where statement is used to select the particular records 
from the input tables/data
9a);
10a)sumput is to write a value to macro variable
symget is to read the value is symput into sas
11a)variables created in macrodefintions are identified as 
local variables or use %put _LOCAL_;
    variables created in OPENCODE are identified as GLOBAL 
variables or use %put _GLOBAL_;

For 10 :

callsymput: We can create macro variable from the dataset    
            variable during the datastep execution time.for 
            this process the data set variable must be 
             existed.

symget:  using with symget function you can create data set 
         variable from the macro variable. for this process 
          macro variable must be existed.

9 ways we create a macro varisbles are
1)%let
2)macro parameter(a,b)
3)%do
4)call symput
5)sql into clause
6)%window
7)%global
8)%local
9)automatic