You can not imagine the difficulty they had ____ the problem. It isn’t ____ easy.
.---David. I’ve lost my keys again. ---Here, not again!You______ your keys.
.Written English is more or less the same in both British and American English _______ the differences in spelling.
.---Do you like cooking, Mary? ---________. Luckily I’ve never had to worry much about it.
.In our school, there is a rule that anyone shouldn’t play computer games during the ______ working time.
.If you compare food costs today ______ of a year ago, you will find the difference.