题目内容：

An image is worth a thousand kilos? Okay, so maybe not a thousand kilos, exactly, but a study shows how a photo diary can keep dieters motivated, making them more likely to achieve their target weight.

Elias Kuzmar Daza, a medical professional from Colombia, studied the motivation levels of patients on weight loss programs at a nutrition clinic.

Different measurements were taken of the patients each week, including body mass index (指标) food and exercise diaries, etc. to record their progress. In addition, full-body photographs were taken each week, which proved to be very motivating and a key factor in patients completing the full program.

Over the course of the sixteen-week program, a full ninety percent of patients, aged between 16 and 72, saw the treatment through to the end, with seventy percent successfully meeting their weight loss aims. Among those monitored, one measurement proved particularly motivating: waistline.

This finding indicates that the majority of the patients who attended the clinic did so motivated by image, rather than any underlying condition. It should be pointed out that eighty percent of them were female.

Another useful finding of this study was that patients did not necessarily need to attend the clinic in person for the program to be effective. A support line was set up, which patients could call to submit their measurements. They also took and sent their own full-body photographs to the researcher. Fifty percent of patients completed the program in this way.

Summarizing the findings, Kuzmar says: “What patients want is a photo, rather than cold numbers.” These photos serve as visual confirmation that all their hard work is paying off, encouraging them on to further weight loss.

1.What is the purpose of the study?

A. To show losing weight is very easy.

B. To compare several ways to lose weight.

C. To prove the effect of images in weight losing.

D. To see how many people can lose weight successfully.

2.How many patients in the clinic reached their weight-loss goals?

A. 50%.    B. 70%.

C. 80%.    D. 90%.

3.What can give people most motivation when they are trying to lose weight?

A. Friends’ encouragement.    B. Others’ strong muscles.

C. Their slimmer waistline.    D. Their standard blood pressure.

4.What must the patients do to complete the weight-loss program?

A. Go to the clinic every week.

B. Call to submit their measurements.

C. Report to the professional every day.

D. Take full-body photographs each week.