A．play with the boy

　　B．get mail from the boy

　　C．listen to the boy's stories

　　D．send mail together with the boy

5．Why does Mike Crenshaw like the last stop of his day?

　　A．It is where he lives.

　　B．It is where he is paid.

　　C．He wants to be with Carter.

　　D．He can finish his work by then.

6．What can we infer from Fredric Rolando's words?

　　A．Mailmen are usually not well respected.

　　B．What letter carriers do is not just sending letters.

　　C．The elderly don't like communicating with others.

　　D．People should learn to recognize and trust each other.

7．What is the best title for the text?

　　A．A letter carrier is praised for helping a kid

　　B．A mailman makes a little boy's dream come true

　　C．Every letter carrier has stops he looks forward to

　　D．The importance of letter carriers cannot be ignored

C

　　Dust on furniture may be bad news for waistlines (腰围). But it's far too early to add dusting to a weight­loss plan. Dietary fats and other materials that make up indoor dust can send a signal to human fat cells, telling them to grow. That process, in turn, might slow the body's rate of burning energy. Such changes could add to any weight problems a person might have.

　　"We don't know what that means to long­term health and certain diseases yet," says Heather Stapleton, one of the study's authors. But she notes that her team's findings also raise a question of whether pollutants (污染物) in dust might play some role in the growing, global problem of obesity.

Stapleton and her colleagues collected dust from homes and offices. Studies found that some materials in the dust could turn on a protein (蛋白质) called PPAR­gamma 1. It's found in many human tissues. Turning this protein on can cause fat cells to grow. Researchers think this protein may be involved in obesity. But a second study now finds evidence that certain fats are mostly to blame. Cooking oils may send out some of these fats into the air, where they eventually find their way into house dust. Or, the authors say, the fats might enter house dust as part of the hair or skin