题目内容：

    Ultrasound（超声）is used widely in medical imaging, but in recent years scientists have started developing it for another use: stimulating nerves to treat disease. In two new studies in mice, researchers focused the sound waves on nerves in the spleen（脾）that communicate with the immune system, reducing symptoms. If the approach proves safe and effective in people, it could serve as a treatment for diseases such as arthritis（关节炎）.

In one study, led by scientists at the Feistein Institute and GE Research, mice receiving a few minutes of ultrasound treatment to the spleen nerve had a diminished symptoms to an injected（注射）poison. In another study, researchers at the University of Minnesota and their colleagues reduces symptoms of arthritis in mice by stimulating their spleen nerves for 20 minutes every day for a week. “Zeroing in on the spleen may provide a more precise approach than focusing on the vagus nerve（交感神经）, which connects with the immune system via a second nerve that stimulates the spleen.” says Hubert Lin, lead author of the latter study. “When we’re targeting the spleen we have less of an effect all over the body.”

“Little is known about how repeated ultrasound affects the spleen or whether it has other harmful effects,” says neuroscientist Denise Bellinger of Loma Linda University, who was not involved in either study. An ongoing clinical trial aims to assess the treatment’s safety in humans with arthritis. A bigger unknown is how ultrasound activates in general. Scientists are now exploring the use of ultrasound on other parts of the nervous system, including the brain. “We know how to control nerves with electricity, and we’ve been doing it for more than 100 years,” neuroscientist Kevin Tracey says, “But the idea of controlling nerve signals with ultrasound is a brand-new field.”

1.What do scientists expect of the new application of ultrasound?

A.It'll be applied in medical imaging

B.It'll be used to activate nerves to treat disease.

C.It’ll be applied in spleen transplantation.

D.It'll be employed to rebuild immune system.

2.What does the underlined word “diminished" in paragraph 2 mean?

A.Complicated. B.Worsened.

C.Decreased. D.Associated.

3.What is the concern of Denise Bellinger?

A.Side effect. B.Time length.

C.The procedure. D.The cost.

4.What is most likely the next step of the study?

A.Assessing the treatment' s safety on humans.

B.Activating nerves in general with ultrasound.

C.Exploring the use of ultrasound on the brain.

D.Controlling nerve signals with ultrasound.