Suppress A New Line Between Select Statements In Sqlplus Script

Spool test.log
SELECT 'FIRST LINE' FROM DUAL;
SELECT 'SECOND LINE' FROM DUAL;
SPOOL OFF;

Then we got the following output,
FIRST LINE
SECOND LINE

But if we want like,
FIRST LINE SECOND LINE

Then, we need to modify the query,

select t1.c1||' '||t2.c2
from (select 'FIRST LINE' c1 from dual) t1,
(select 'second LINE' c2 from dual) t2;