這是一個(gè)成功的主題段，請注意這段話段落細(xì)節(jié)展開的幾種形式-提供事實(shí)、舉例、個(gè)人經(jīng)歷和描述。我們把這個(gè)段落拆分后進(jìn)行分析：

Topic sentence
　　　　　　（主題句）
The Smithsonian Institution is worth visiting for a number of reasons.

Supporting idea 1
　　　　　　（支持理由1）
The Smithsonian Institution comprises various museums that offer something for everyone.

Details—facts
　　　　　?。?xì)節(jié)展開-提供事實(shí)）
These museums include the National Museum of History and Technology, the National Aeronautics and Space Museum, the National Collection of Fine Arts, the National Museum of Natural History, and several others.

Supporting idea 2
　　　　　　（支持理由2）
A person can do more than just look at the exhibits.

Details—examples
　　　　　?。?xì)節(jié)展開-舉例）
For example, in the insect zoo at the National Museum of Natural History, anyone who so desires can handle some of the exhibits.

Supporting idea 3
　　　　　?。ㄖС掷碛?）
The museums provide unforgettable experiences.

Details—personal
　　　　　　experience
　　　　　　（細(xì)節(jié)展開-個(gè)人經(jīng)歷）

　　　　　　
In climbing through the Skylab exhibit at the National Aeronautics and Space Museum, I was able to imagine what it would be like to be an astronaut in space.

Supporting idea 4
　　　　　?。ㄖС掷碛?）
Movies shown at regular intervals aid in building an appreciation of our world.

Details—description
　　　　　?。?xì)節(jié)展開-描述）
In the National Aeronautics and Space Museum, there is a theater that has a large screen. When the movie is shown, it gives the viewer the feeling that he or she is in the movie itself, either floating above the Earth in a hot-air balloon or hang gliding over cliffs.