compose-message

Step 4: Compose a request message.

步骤4：编写请求消息。

One conclusion researchers made about why texting is so dangerous is the length of time it takes to compose a message while driving.

为什么开车时发短信如此危险呢？ 研究人员得出的结论是，问题就出在编写短信的那段时间。

Message types. These are used to compose complex messages from existing data types and primitive types.

消息类型。这些是被用来从现有的数据类型和原始类型组成的复杂消息。