Vitamin D helps our bodies make a special chemical，and this special chemical，________，affects our brains，making us feel happy.
| A．in turn | B．in particular |
| C．in advance | D．in short |
He ______ prison two years ago and now he _______.
| A．was put in; was set free | B．was shut into, is set free |
| C．put into, has been set freely | D．was put into; has been set free |
_______ the two oceans the Pacific is ______ .
| A．In; the large | B．For; larger | C．Of; larger | D．Of, the larger |
If city noise _______ from increasing, people _______ shout to be heard even at the dinner table 20 years from now.
| A．are not kept; will have to | B．are not kept; have to |
| C．do not kept; will have to | D．do not kept; have to |
I _____ ten minutes to decide whether I should reject the offer.
| A．gave | B．was given | C．was giving | D．had given |
______ the day on, the weather got worse.
| A．With | B．Since | C．Which | D．As |