He said ________ he was doing his homework.
A. if B. when C. that D. where
She asked ________ I was a teacher.
A. if B. when C. that D. where
He knew ________ he should work hard.
A. if B. when C. that D. where
I've decided to go to London next week. I was wondering you could go with me.
A. if B. when C. that D. where
I can't decide ________ to buy this bike or not.
A. when B. whether C. if D. where
— I'm not sure ________ there are living things on other planets or not.
— Even scientists aren't sure about it.
A. whether B. where C. why D. that
