题目内容：

Something in chocolate could be used to stop coughs and lead to more effective medicines, say UK researchers.

Their study found that theobromine, found in cocoa, was nearly a third more effective in stopping coughs than codeine, which was considered the best cough medicine at present.

The Imperial College London researchers who published their results online said the discovery could lead to more effective cough treatment. “While coughing is not necessarily harmful,  it can have a major effect on the quality of life, and this discovery could be a huge step forward in treating this problem,” said Professor Peter Barnes.

Ten healthy volunteers were given theobromine, codeine or placebo, a pill that contains no medicine, during the experiment. Neither the volunteers nor the researchers knew who received which pill. The researchers then measured levels of capsaicin, which is used in research to cause coughing and as a sign of how well the medicine are stopping coughs.

The team found that, when the volunteers were given theobromine, the capsaicin need to produce a cough was around a third higher than in the placebo group. When they were given codeine they need only slightly higher levers of capsaicin to cause a cough compared with the placebo.

The researchers said that theobromine worked by keeping down a verve activity(神经活动), which cause coughing. They also found that unlike some standard cough treatments, theobromine caused no side effects such as sleepiness.

1.According to Professor Barnes, theobromine ______.

A. cannot be as effective as codeine    B. can be a more effective cure for coughs

C. cannot be separated from chocolate    D. can be harmful to people’s health

2.What was used in the experiment to cause coughing?

A. Capsaicin.    B. Codeine.

C. Theobromine.    D. Placebo.

3.We learn from the text that volunteers in the experiment _____.

A. were patients with bad coughs    B. suffered little side effects

C. received standard treatments    D. were divided into the three groups

4.Which of the following would be the best title for the text?

A. Codeine: A New Medicine    B. Cough Treatment: A Hard Case

C. Chocolate May Cure Coughs    D. Theobromine Can Cause Coughs