In the context of argumentation, providing support for an assertion means that the speaker is backing up their claim with evidence or reasoning. In this case, the assertion is that 'The world is very different now,' and the underlined passage serves to reinforce this claim by offering supporting details or examples. This is a fundamental aspect of effective argumentation, as it helps to persuade the audience by demonstrating the validity of the speaker's point of view. Acknowledging opposing arguments is also important in argumentation, but it serves a different purpose, which is to show that the speaker is aware of other perspectives. An assertion is simply a statement made by the speaker without necessarily providing support.