I regret _____ hard at school, or I would have succeeded in passing the exam.
American English is more or less different____British English______pronunciation and spelling.
He asked ______for the new mountain bicycle.
What on earth did you tell her? The_____on her face suggested that she was very angry.
Rather than________in the city, the old man would prefer______in the count、ryside.
People in the west make_____a rule to buy Christmas presents for their relatives and friends.