( ) you were a member, you could come too.
a. that b. if c. than d. so

( ) i was clean, i took a bath.
a. what b. as long as c. such d. even though

i wanted to ( ) down because i was quite tired.
a. lie b. bring c. lay d. take

while ( ) my new book, i learned something interesting.
a. to read b. read c. to reading d. reading