TASK DEFINITION: Given a text, write a compressed version of it in a single sentence.
PROBLEM: True, the Gettysburg Address was not legally binding, but preambles are never meant to have the status of positive law. They are designed to explain why it is necessary for the government to bind itself to certain objectives.

SOLUTION: The Gettysburg Address wasn't legally binding, but preambles aren't meant to have positive law status, but rather to explain why its necessary government to bind itself.

PROBLEM: Table 5 shows that, using the average labor cost for all bargaining employees, the profit drops to $283 million. The profit from serving all rural routes is obviously highly sensitive to the labor cost of rural carriers.

SOLUTION: Using the average labor cost for all bargaining employees, the profit drops to $283 million. THe profit from rural routes is highly sensitive to the labor cost.

PROBLEM: "Outside the farmyard, but still (usually) within farmland territory, the crow and rook are both named for their harsh call or caw , and though less common, the chough and the raven are similarly named."

SOLUTION:
The crow and rook are both names for harsh call or caw, and less commonly called chough and the raven.