Stephen Hawking believes that the earth is unlikely to be the only planet _______ life has developed gradually.
A．that B．where C．which D．whose
The sleeping baby would be scared _______ a sudden loud noise.
A．was there B．there was
C．should there be D．there should be
--David, are you 1istening to me?
---Sorry, Dad. I _______ to make sense of what the reporter said.
A．was trying B．have tried C．am trying D．tried
Many approaches have been _______ to control the spread of H7N9 Bird Flu.
A．adapted B．employed C．negotiated D．accessed
Roger had just walked into his office and that was when he was told that his plan had finally been approved. Which of the following can be instead of the underlined(划线的) part to make the sentence better.
A．and then they told him B．when it was learned by him
C．and then he learned D．when he learned
The sunspot came into its active stage, __________ that happens once every eleven years.
A．one B．it C．the one D．what
