—It cost me 30 yuan to get there. —Well, it was crazy of you to take a taxi ______ you would come by bus as well.
Just as sound travels through the air in waves, electricity travels through the air in ______ radio waves.
It was _____ of Jack to turn off the radio when I was sleeping in the bedroom.
A student will be immediately dismissed if he/ she is found _____ in school.
I failed again in the exam and only then _____ how much time I had wasted.
—Mom. May I play computer games just for a while?—______ ! Dad is writing his paper.