第6条  条件关系:
A. 阅读下列句子，它们均使用了if。改写每个句子，用它下面所附的黑体词语替代if。在某些句子中你可能还要酌情删去一些词语。
1. You can borrow my dictionary if you return it before you go home.
   providing that
2. You can't go to university if you don't have good grades.
   unless
3. Pollution will get worse if we continue to live in a throwaway society.
   as long as
4. Many developed countries are willing to waive the Third World debt if the money is reinvested in education and medicine.
   on condition that
例1 （4896）However, there is almost another route to take   81  you are not in a hurry.
A. unless         B. if        C. as        D. since   
例2 （4956）Even those who had little or no training in science might not have made their inventions   89  a groundwork had not been laid by scientists years before.
A. as        B. if         C. because       D. while 
例3 （981）We judge race usually from the coloring of the skin. --- But   63  you were to remove the skin you could not tell anything about the race to which the individual belonged.
A. since      B. as         C. if          D. while
unless (Ⅸ4976/61)
例4 （976）Most children with healthy appetites are ready to eat almost anything that is offered to them, and a child rarely dislikes food  61  it is badly cooked.
A. if        B. until       C. that         D. unless
例5.   75  equal educational advantages, there will be no difference in average standings, either on account of race or geographical location.
A. Provided      B. Concerning      C. Given     D. Following
例6 （4011）Professors should avoid repeating in lectures material that is in the textbook. “  86  we’ve read the material, we want to discuss it or hear it elaborated on, not repeated.”
A. Once      B. Until        C. However      D. Unless
if (4896/81；4956/89；4976/61；4981/63)，unless (4896/81；4976/61； 4011/86) lest (4976/78)  given（Ⅹ4981/75）provided(4981/75) once( 4011/86)
until (4011/86)
D. 有些名词可用于表示条件。从下面句子的A，B，C三个选项中选出一个完成句子。
1. Being able to drive is one of the   of the job of salesman.
   A. pre-requirements    B. prerequisites    C. prescriptions
2. Before you accept a job, it is important that you agree with the __    of the contract.
   A. conditionals    B. conditions   C. conditioners
3. It is a   of the university that you attend an interview.
   A. requirement   B. requisite (必须品)    C. requiem   
requiem 天主教的 “安灵弥撒”
requisition 必备条件，reservation 附加条件，restriction 带限制性条件