nerves in your legs and feet. It can cause numbness and/or temporary paralysis in the legs, ankles, or feet. While the feeling of discomfort may only last a minute or two, repeatedly crossing your legs until they feel numb can cause permanent nerve damage.

　　So next time you sit down, try to get yourself in the habit of sitting with both of your feet on the floor. Not only will it help your posture and stability, but it will also save your health in the long run.

1. According to para 2, we can infer that___________

A. it's no big deal to cross our legs for less than 15 minutes.

B. we will feel uncomfortable at the moment we cross the legs.

C. we should take a walk every hour after sitting still.

D. crossing legs while sitting makes it harder to circulate our blood.

2. How many health problems can be caused by crossing legs according to the text?

　　A. 2 B3 C.4 D. 5

3. Which of the following best shows the structure of the passage?

　A. ① B ① C. ① D. ①

② ③ ② ③ ② ③ ④ ② ③

④ ⑤ ④ ⑤ ⑤ ④ ⑤

　　Microsoft has developed a new smartphone app that interprets eye signals and translates them into letters, allowing people with motor neurone disease to communicate with others from a phone.

　　The GazeSpeak app combines a smartphone's camera with artificial intelligence to recognize eye movements in real time and convert them into letters, words and sentences.

　　For people suffering from ALS（渐冻症）, also known as motor neurone disease, eye movement can be the only way they are able to communicate.

"Current eye-tracking input systems for people with ALS or other motor