Fill in the blanks with the suitable conjunction:
Let us wait here _____ the rain stops.
Leena was _________ intelligent _________ goodlooking.
such..that
as....so
both...and
whether..or
My grandfather is very old , _________ he has a sharp memory.
because
while
however
so
You must concentrate in your studies__________ you will fail.
Otherwise
Until
Only if
although
The batsman had to retire _____ of an injury.