单选题 18. "If not us, who? If not now, when?" These two questions are used as a __________.

单选题 16. The woman had persuaded him to do __________ he was hired never to do -- reveal the combination for the lock on the entrance.

单选题 12. __________ the attempted rescue mission, the hostages might still be alive.

单选题 14. Writers often coupled narration with other techniques to develop ideas and support opinions that otherwise __________ abstract, unclear or unconvincing.

单选题 13. Members of parliament were poised __________ ahead with a bill to approve construction of oil pipeline.

单选题 11. Moving from beginning to end by order of time, narration relies on a more natural pattern of organization than __________.

单选题 17. The bad news was that he could be a very dangerous person __________ he choose to be.

单选题 15. Protocol was __________ enabled him to make difficult decisions without ever looking back.