2．What has an effect on people most?

　　A．Raising heads to others.

　　B．Doing something casually.

　　C．Meeting in the school corridor.

　　D．The simple act of saying "Hello"．

　　D　解析：细节理解题。根据第二段第二句"Still, on a smaller range, the simple act of saying 'Hello' to someone can make a lot of difference."可知， 对别人影响最大的是打招呼这种简单的行为。

　　3．Why do some people feel lonely?

　　A．They are unwilling to communicate with others.

　　B．They are too shy to communicate with others.

　　C．They are very fond of living alone.

　　D．They don't like doing things as others do.

　　B　解析：推理判断题。根据第四段中的"Many people are lonely because they're shy...cut off."可知， 一些人感到孤独的原因是他们太害羞了，不敢和别人交流。

　　4．What can we learn from the last paragraph?

　　A．We should neglect a small thing.

　　B．Saying "Hello" to others is powerful.

　　C．The flowers make the world better.

　　D．No one is better than Joseph Joubert.

　　B　解析：推理判断题。根据最后一段中的"A 'Hello' to a stranger is a small thing, and often neglected(忽视), but through it we can make the world better for another person."可知，向别人打招呼是有影响力的。

　　B

(2019·长沙名校第二阶段测评)Scientists found gravitational waves as they watched the effects of two black holes running into each other and forming a much bigger one, a century after Albert Einstein