28. Vitamin D helps our bodies make a special chemical, and this special chemical, _______, affects our brains, making us feel happy.
He was busy writing a story, only once in a while to smoke a cigarette.
I like getting up very early in summer. The morning air is so good .
The wet weather will continue tomorrow, when a cold front to arrive.
When he the door, he found his keys were nowhere.
My parents in Hong Kong. They were born there and have never lived anywhere else.