完形填空(第51～65題，每題1分，共15分)。閱讀下面的短文，文中有15處空白，每處空白給出了4個選項，請根據短文的`內容從4個選項中選擇1個最佳答案，塗在答題卡相應的位置上。
Cost as a Factor in Supply
In a purely competitive market,the supplier of goods and services has no control over the market price,because he produces too little to influence market no difference between his products and the products (51) his competitors,he will sell nothing if he charges above the market price and he will sell all if he charges at or (52) the market ver,in considering the price,he must take the (53) of production into e are times when he may be willing to sell below his might happen when prices tumble for (54) he believes will be a short ver,no business person can (55) to lose money for a prolonged must be constantly (56) of his costs in relation to the market price if he is to competes successfully and earn a profit.
Many people have the impression that as production increases,costs per unit decrease.(57) mass production has made this true in certain industries and at certain levels of production,(58) logic and practical experiences have shown that costs per unit begin to rise beyond a certain level of economists (59) to this principle as the law of increasing costs.
The reason costs rise as production goes up is (60) However,it is easy to recognize that as production goes up,the need for additional factors of production will also grow,(61) competitive bidding in the marketplace for the factors of a producer needs (62) skilled labor to produce more,and none of this labor is unemployed,the producer will have to get (63) from other can be done by (64) higher er bidding would also apply to the other factors of must also recognize that not all labor is equally productive,(65) not all land is equally fertile and not all ore (礦石) is equally rich in the mineral wanted.
51、
52、w ath e
53、e h it
54、
55、rd end r
56、 id e icious
57、use e e
58、 her
59、rt r nd
60、r le icult lex
61、ging lting in uding ying out
62、 rous
63、 e e
64、ring ing cing ng
65、 if as use e
