33.Only after he had spent several nights working on the math problem_______to wonder whether the problem was wrongly set.
As we all know, the functions of our skin are very .
--- Can I come and have a look at your new house? --- Yes, !
It is generally accepted that boy must learn to stand up and fight like man.
The islands developed on their own for 80 million years and ________ have many rare animals found nowhere else.
She is a crazy fan of this singer. ________ she listens to his songs hundreds of times, she will never get tired.