你给我打电话时，我正站在图书馆的前面。
I________ ________in front of the library when you________ ________．
昨天晚上我妈妈很快就睡着了。
My mother________ ________soon last night．
（2014广东）Most people are________building a paper factory near here．They are worried the river will get polluted．
A．for
B．with
C．against
D．beyond
Yesterday evening I was playing the piano________the doorbell rang．
A．when
B．before
C．while
Tony________TV when his mother came in．
A．watch
B．watches
C．was watching
D．is watching
（2013天津）I saw him in the library yesterday．He________a book at that moment．
A．reads
B．is reading
C．was reading
D．will read
