He hurried to the school only _______ the campus was empty ___ it was Sunday!.
| A．find; because | B．found; because of | C．to find; because of | D．to find; because |
When I talked with my grandma on the phone ,she sounded weak , but by the time we ____up ,her voice had been full of life.
| A．were hanging | B．had hung | C．hung | D．would hang |
—Why does the lake smell terrible ?
--because large quantities of water ____.
| A．have polluted | B．is being polluted | C．has been polluted | D．have been polluted |
My parents have promised to come to see me before I ___for Africa.
| A．have left | B．leave | C．left | D．will leave |
The way the guests____in the hotel influenced their evaluation of the service.
| A．treated | B．were treated | C．would treat | D．would be treated |
Over the past decades , sea ice _____in the Arctic as a result of global warming.
| A．had decreased | B．decreased | C．has been decreasing | D．is decreasing |