几道题,供讨论

九山环一湖

Escalating worldwide demand for corn has led to a sharp increase in the market price of corn, and corn prices are likely to remain high.  Corn is extensive used as feed for livestock, and because profit margins are tight in the livestock business, many farmers are expected to leave the business.  With fewer suppliers, meat prices will surely rise.  Nonetheless, observers expect an immediate short-term decrease in meat prices.

Which of the following, if true, most helps to justify the observers’ expectation?

The increase in corn prices is due more to a decline in the supply of corn than to a growth in demand for it.

Generally, farmers who are squeezed out of the livestock business send their livestock to market much earlier than they otherwise would.

Some people who ate meat regularly in the past are converting to diets that include little or no meat.

As meat prices rise, the number of livestock producers is likely to rise again.

Livestock producers who stay in the business will start using feed other than corn more extensively than they did in the past

A significant number of complex repair jobs carried out by Ace Repairs have to be reworked under the company’s warranty.  The reworked jobs are invariably satisfactory.  When initial repairs are inadequate, therefore, it is not because the mechanics lack competence; rather, there is clearly a level of focused concentration that complex repairs require that is elicited more reliably by rework jobs than by first-time jobs.

The argument above assumes which of the following?

There is no systematic difference in membership between the group of mechanics who do first-time jobs and the group of those who do rework jobs.

There is no company that successfully competes with Ace Repairs for complex repair jobs.

Ace Repairs’ warranty is good on first-time jobs but does not cover rework jobs.

Ace Repairs does not in any way penalize mechanics who have worked on complex repair jobs that later had to be reworked.

There is no category of repair jobs in which Ace Repairs invariably carries out first-time jobs satisfactorily.

不懂

Each species of moth has an optimal body temperature for effective flight, and when air temperatures fall much below that temperature, the moths typically have to remain inactive on vegetation for extended periods, leaving them highly vulnerable to predators.  In general, larger moths can fly faster than smaller ones and hence have a better chance of evading flying predators, but they also have higher optimal body temperatures, which explains why ______.

large moths are generally able to maneuver better in flight than smaller moths

large moths are proportionally much more common in warm climates than in cool climates

small moths are more likely than large moths to be effectively camouflaged while on vegetation

large moths typically have wings that are larger in proportion to their body size than smaller moths do

most predators of moths prey not only on several different species of moth but also on various species of other insects

robertchu

B, A, B.
Q1 those farmers who will leave the business are going to send theirlivestock to market soon, which will cause a temporary over-suuply.
Q2: has been discussed earlier.  lease search this board.
Q3:
1) large moths have higher optimal body temperature --> in coolclimates they can't fly (while small moths are still able to fly)--> more eaten by predators;
2) large moths fly faster --> in warm climates they can better survive predators than small moths