13. –Just now I called home but nobody answered.
--Oh, sorry. I ________.

He chose to teach in a western province, though he _______ in the city for a better life.

Shopping online can save much time as you _______ go to a shop or walk around crowded
shopping centers.

In that hospital under no circumstances any member of staff___socialize with the patients .

We______every day for almost two weeks ,so I’ll need to buy a large backpack to carry my supplies .

---It’s supposed to rain tomorrow.
---I know, but the forecast ___ be wrong. Weather forecasts are far from 100 percent accurate.    

13．－Where will you start your work after graduation?
－Mum, it's not been decided yet. I_______continue my study for a higher degree.

－Mary, how did your Math test go?
 －I had thought I _________, but in fact I came in the top 10% in my class.

 
16．—Where is Lily, Lucy? I cannot find her anywhere.
—She_________have been off long. I saw her clean the window just now.

23. Your room is terribly dirty; you        get it cleaned in two hours, or Mum will be angry.