1. The train __ at 8 am next Friday. arrives is going to arrive will arrive is arriving

The correct answer is "will arrive."<br /><br />Explanation: The sentence is talking about a future event that is scheduled or planned, which is the train's arrival at 8 am next Friday. In English, the future simple tense (will + base form of the verb) is used to express scheduled or planned future events. Therefore, "will arrive" is the correct choice.