Only by increasing the number of doctors by 50 percent ________ properly in this hospital. (2013·大纲全国,32)
_________ found my wallet, Tom?
It was not until 1920_________ regular radio broadcast began.
It was in the factory _________ produced TV sets _________ I got to know her.
Factory workers have to work very hard, and _________.
Only when David did it a second time _________.