“如果一个犹太人看到另外一个犹太人在街边开了一家餐馆，他会考虑开家洗车行。”这告诉我们正确参与竞争必须（  ）

    Writing text messages (短信）while walking is dangerous. A study says it is more dangerous than texting while driving. Researchers found that there are more____(injure) to texting pedestrians (行人) than there are to texting motorists. Their report says walking is not as easy____we think. We must focus on many things at the same time to walk safely in a straight line. The researchers said that people forget how to walk____(proper), so dangerous things happen to them. They bump into walls and other people. They walk into cars, fall over things in the street, and even fall into holes____down stairs.

    A professor said walking is a difficult action. There are several reasons ____texting makes walking dangerous.____is that people cannot see the street. Another is that they focus on their phone keyboard instead of their feet. A final reason is that their minds are somewhere else — they are not thinking about____(walk) from A to B safely. The professor said over 6,000 people____(visit) his hospital last year because of texting. He said____worst cases are head damage. When a pedestrian is tossed into the air he/she has nothing____(protect) the head. The damage can be serious.

青藏高原是我国夏季气温最低的地方，导致这一现象的主要影响因素是（   ）

清朝后期，揭开变法维新运动序幕的事件是（　　）