For those whose hearts often go off beat, pacemakers(心脏起搏器) are life savers. By providing a small electrical support at the right moment, they can keep a heart working properly. Their main problem is that they use batteries. Even the best of them will run out of energy, and changing the batteries requires operations. Since operations are usually best avoided, the search has been on for long-lasting batteries. Different choices have been explored for a long time. Today, pacemakers with lithium(锂) batteries last between 5 and 15 years.

Zhang Hao, from Shanghai Second Military Medical University, and Yang Bin, from Shanghai Jiao Tong University, tried a way to refill a pacemaker’s battery with electricity(电) by getting energy from inside the body. They report in the magazine ACS Nano that they have also used the heart muscle(肌肉) itself to work. Earlier efforts by other scientists to use heart muscle power to run pacemakers depend on piezoelectric materials(压电材料). These materials can be connected to a beating heart and produce electricity when they are slightly deformed(弯曲). This has worked, but not well enough: the output has rarely been over 5 microwatts(微瓦), while most pacemakers require at least ten.

Dr Zhang and Dr Yang believed that they could improve the matters by making their piezoelectric materials more dramatically deformed, and then produce 15 microwatts, because the more deformed, the more electricity will be produced. They put their idea to the test in a 50kg pig. It made enough electricity for the pacemaker to work as expected.

Whether such an idea will pass human tests remains to be seen. But if it does, the days of pacemakers that need battery changes through operations may not last long.

1.1.According to the first two paragraphs, what is a problem with pacemakers?

A They often go off beat.

B Their energy can be used up.

C Operations often influence them.

D They sometimes do harm to hearts.

解析：选B。细节理解题 解析：第一段明确指出心脏起搏器的主要问题是使用电池，且电池会耗尽（run out of energy），更换电池需要手术。因此答案为B。

2.2.From this passage, what do we know about piezoelectric materials?

A They can be used to produce electricity.

B They can deform the heart to make it beat faster.

C They were first used by Zhang Hao and Yang Bin.

D They were proved to produce 15 microwatts in human tests.

解析：选A。细节理解题 解析：第二段提到压电材料在弯曲时可以产生电（produce electricity），因此A正确。其他选项与原文不符：B未提及，C并非首次使用，D尚未进行人体测试。

3.3.What does the word “dramatically” in the 4th paragraph most probably mean?

A Comfortably.

B Safely.

C Greatly.

D Rapidly.

解析：选C。词义猜测题 解析：根据后文“the more deformed, the more electricity will be produced”可知，变形程度越大，发电量越大，因此“dramatically”应表示“大幅度地”，与C（Greatly）

4.4.What is the best title for this article?

A No Need to Use Pacemakers

B The Problem with Piezoelectric Materials

C The Contribution of Chinese Scientists to Heart Operations

D Chinese Scientists Found a New Way to Improve Pacemakers

解析：选D。主旨大意题 解析：文章主要讲述中国科学家通过压电材料改进心脏起搏器，使其从心脏肌肉中获取能量，减少电池更换手术。D最全面概括了核心内容。