2681．I was woken by a crash of thunder yesterday evening.

2682．到上學(xué)期末，我們已讀了十篇短篇小說。
By the end of last term .

2683．For many of us，meeting new people can be really horrible.How many times have you been invited to an event — a party，dinner with a friend and their friends，lunch with a business associate，a weekend away with a friend or your partner and their family and friends — and turned it down for the comfort and safety of your own home？For the sincere social butterflies in the world，meeting new people can be exciting and fulfilling.However，for those who struggle with social anxiety，the mere thought of meeting new people can cause significant anxiety and even panic symptoms.
   Social anxiety as a whole is a complex issue.It appears in numerous forms，and has many possible reasons for finding its way into our lives.As with everything else，there are also varying degrees of anxiety that is experienced from one person to the next.For this reason，there are three parts to discuss：Part 1：What does social anxiety look like？Part 2：Where does social anxiety come from？Part 3：What can be done to get past social anxiety？
   There are times in our lives when we get tired，or there is a great movie on TV and we just want to lie lazily on the couch with a meal or dessert — so we choose not to go out.This is not social anxiety.The motivation here isn't to avoid uncomfortable symptoms associated with socializing.This was merely a decision and desire to do something at home.
   Although social anxiety appears in different ways，the link among them is the feeling of anxiety or panic that，at its most basic level，is caused by fear of embarrassment，judgement or rejection by others.It mostly appears when the social situation involves meeting new people.However，it can also exist with people we have known for a long time.It is common for people to completely avoid social situations，or still go out and socialize while just trying to "get through it" and go home.
__________

2684．The most important thing ______ we should consider is the first idea _____ he has talked about in the speech.（　　）

2685．There are thirty （microscope） in our chemical laboratory.

2686．We can't solve the problem we can travel faster than light.

2687．The girl stepped on a stone and unluckily twisted her left （腳踝）.

2688．About half of them are children，and another 8%are （年老的）.

2689．academic adj. – n.?？圃盒?/div>

2690．Crossing your legs is an extremely common habit；most people don't even notice that they're doing it when they sit down.While you may find it comfortable to sit with one knee crossed over the other，it might be causing health problems that you are not aware of.
   A study published in Blood Pressure Monitoring stated that sitting with your legs crossed can increase your blood pressure.The reason for this is that the blood in your legs has to work against gravity to be pumped back to your heart and that crossing one leg over the other increases resistance，making it even harder for the blood to circulate.This causes your body to increase your blood pressure to push the blood back to the heart.You won't feel any immediate effects，but repeated，drawn-out increases in blood pressure can cause long-term health issues.So，planning to sit for a long period of time？Don't keep your legs crossed.
   Crossing your legs at the knee can also cause pressure on the major nerve in your leg that passes just below your knee and along the outside of your leg，explains Richard Graves，a medical expert.This pressure can cause numbness and temporary paralysis （麻痹） of some of the muscles in your foot and leg，preventing you from being able to raise your ankle-what we know as that "pins and needles" sensation.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）What can we learn about crossing one's legs？
A．It is a very bad social habit.
B．It is usually practiced deliberately.
C．It can do harm to people's health.
D．It can make others feel uncomfortable.
（2）According to the study，sitting with your legs crossed can .
A．a(chǎn)ffect your blood pressure
B．resist gravity effectively
C．lead to heart attacks easily
D．improve the function of legs
（3）In the third paragraph "pins and needles" probably means .
A．slight sharp pains
B．being a little nervous
C．serious muscle injuries
D．being highly flexible
（4）What is the main purpose of the text？
A．To compare common habits.
B．To give readers some advice.
C．To evaluate effects of an experiment.
D．To introduce research methods.