People in the United States don't always shake hands when they are introduced to one another. However, in a formal or business situation people almost always shake hands.
美国人彼此介绍相识时，不一定要握手。但在正式场合或公务交往中，则几乎都要握手。

A: Mary, this is Joe's brother David.
B: I'm very glad to meet you.
C: It's a pleasure to meet you.
B: How do you like Texas so far?
C: It's really different from what I expected.
B: Don't worry. You'll get used to it in no time.

玛丽，这是乔的兄弟戴维。
认识你很高兴。
幸会，幸会。
这些天来，你觉得得克萨斯州怎么样？
确实和我想象的不一样。
别担心，你很快就会习惯的。