The idea of fish being able to produce electricity strong enough to light a lamp is almost unbelievable, _____ several kinds of fish are really able to do this.

Sally worked late in the evening to finish her report _____ her boss could read it first thing next morning.

John knocked at the door for nearly five minutes____his wife opened it.

--- Are you familiar with the music ?
--- Yes. There was a time _____ this kind of music was quite popular.

-- Would you like to come to the dinner party here on Saturday ?
　 ---Thank you. I'd love to, _____ I'll have to finish all my homework before the weeked, otherwise, my parents won't let me go.]

  The boy is not ________ he used to be; he looks ________.

  The population of the country is 3 million, _____ Kooris.

  It will be a long time ______- he returns.

  The natives could live for thousand years in the desert land _______ a foreigner could starve.

  __________ I got home, the clock struck 12.