___used to be thought that the earth was square.
17.Now, boys,I’ll_________the story where I stopped yesterday.
16.It is usually not quite cold in this area in March,but sometimes temperature_______low.
15.Jack was once a common name,___________,I think, that is seldom chosen nowadays.
14.-The weather isn’t good enough for an outing,is it? -To much dust.We can’t have__________at this time of the year.
13.Subway Line 4,__________into use in September 2009,has made traveling in Beijing easier.