请用所给动词的适当形式填空(共6小题;每小题1分, 满分6分)
So far, people ____________ (not find) the plane from Malaysia to Beijing.
When workers asked for better working conditions, the boss didn’t know how _____________
(deal) with the situation.
When I was a child, I once dreamed of ____________ (receive) a letter from the queen in the UK.
---I’m afraid you can’t park your car in front of our school. Look at the sign, please.
---Sorry, I ____________ (not see) it.
Simon, together with his classmates, ____________(search)the Internet in the classroom when the teacher went in.
Could you tell me when the theme park ____________ (open) in summer?