1 . 我听到了好像焰火的声音。   I heard ________   ________   ________ fireworks.

2 . After a heated discussion, they still don’t know at all _______.

A．what is he working out	B．what he is working on
C．what did he work on	D．what he is working out

3 . One theory    this phenomenon    acupuncture reduces pain suggests that acupuncture_____ pain signals from reaching the brain.

A．explaining; that; should block	B．which explains; where; can block
C．that explains; where; block	D．explaining; that; blocks

4 . Donald. J. Trump insists that he ______ the phone in his Government office all the time, instead of his own cellphone and that the New York Times ______ the fake news.

A．uses; stops	B．use; stops
C．uses; stop	D．use; stop