**Rule:** The Future Continuous Tense (will be + verb-ing) is used to describe a future action that will be in progress when another action happens. The action of 'talking' will be ongoing at the moment the phone call comes in. Option (b) suggests the talking will start at that moment, which is less likely.

**Rule:** The Future Perfect Passive voice (will have been + past participle) is used because the subject ('package') is receiving the action, and the action will be completed by a specific future time ('by this time tomorrow'). Option (a) is future continuous active. Option (b) is simple present active. Option (d) is simple present passive.

**Rule:** The Simple Future with 'will' is used for making predictions. Adverbs like 'probably', 'perhaps', or 'maybe' are often used with 'will' to show the degree of certainty. This is a general prediction about the weather. 'is going to rain' would be used if there were visible dark clouds (present evidence).

**Rule:** In reported speech, when a promise about the future is reported, 'will' is often retained to reflect the original promise. 'The politician promised, "Taxes will not increase."' Thus, 'will not increase' is the correct form. Option (c) 'would not increase' would be used if the reporting verb was in the past (e.g., 'He promised he would...').

**Rule:** The Future Continuous Tense (will be + verb-ing) can describe an action that will happen in the normal course of events in the future. It's a prediction of what will be happening at that moment. When the concert ends, the process of people leaving will be in progress. Option (b) 'will have poured' suggests the action will be complete, which is unlikely at the exact moment the concert ends. Options (c) and (d) are incorrect tenses.

**Rule:** The Future Perfect Tense (will have + past participle) is used to express that an action will be completed before another future event. The speaker predicts that the action of the best seats being taken ('gone') will be finished before they manage to get their tickets. Option (a) does not emphasize this completion.

**Rule:** The 'be going to' future is used to talk about intentions or plans. It is implied that the new CEO has an intention to make changes. It is a prediction of future events based on present knowledge. Option (b) is also possible for future plans. Option (a) is incorrect. Option (d) is present perfect.

**Rule:** The Simple Present Tense is used to talk about future events that are part of a program or schedule. A TV show broadcast time is a scheduled event. 'is on' is the idiomatic way to say this. Option (c) is also possible, but (a) is more common and concise for TV schedules.

**Rule:** The Present Continuous Tense ('is/are' + verb-ing) is used to talk about fixed, official arrangements for the future. A formal opening is a scheduled event. Option (d) 'will be opening' is also a correct and slightly more formal way to express this. Option (b) is for repeated schedules. Option (c) is a simple prediction.

**Rule:** This is a First Conditional structure, even though the 'if' clause is embedded. The main clause describes the likely future result of the condition. Therefore, the Simple Future ('will cause') is the correct tense to use for the result. Option (a) is simple present. Option (c) is present continuous. Option (d) belongs to the third conditional.