**Rule:** In conditional clauses starting with 'unless' (or 'if'), the Simple Present Tense is used to refer to the future condition. The main clause uses a future tense ('the situation will get worse'). Using 'will' in the 'unless' clause is a common grammatical error. Option (d) is past tense.

**Rule:** The Simple Present Tense is the most standard and formal tense for events on a fixed public timetable, such as train departures. While other future forms like (a) and (d) are common in speech, (c) is the technically correct form for a schedule.

**Rule:** The Future Perfect Continuous Tense (will have been + verb-ing) is required to emphasize the duration ('for six months') of an action leading up to a specific future event ('by the time the race starts'). It highlights the long period of preparation. Option (b) doesn't convey the duration. Options (a) and (c) are incorrect.

**Rule:** To ask a question about whether an action will be completed by a specific future time, the interrogative form of the Future Perfect Tense is used. 'By the deadline' indicates the need to check for completion. Option (b) asks if the action will be in progress. Options (c) and (d) are present tenses.

**Rule:** The sentence contains a future time clause ('When their new album is released'). The main clause must describe the subsequent future event. The Simple Future ('will go') is the most appropriate tense to state the planned action that will follow the album release. Option (b) is also possible for plans.

**Rule:** The Future Continuous Tense (will be + verb-ing) can be used to explain why you cannot do something in the future. It refers to an action or state that will be in progress and is part of your existing plans. It's a polite way of stating a prior arrangement. Option (b) is also possible but less common in this specific explanatory context.

**Rule:** The negative Future Perfect Tense (will not have + past participle) is used to state that an action will not be completed by a specific future deadline. The speaker is predicting that the arrival will not be a completed action by 'tomorrow morning'. Option (d) describes an action that won't be in progress.

**Rule:** The Future Continuous Tense (will be + verb-ing) is used to say that an action will be in progress at a specific time in the future. The time '10 o'clock tomorrow' is when the meeting will be happening. Option (b) means the meeting will be over by 10. Option (a) is incorrect. Option (d) is grammatically incorrect.

**Rule:** 'Shall' is used with 'I' and 'we' in interrogative sentences to make an offer or a suggestion, or to ask for advice. 'Shall I close the window?' is a classic example of offering to do something. Option (a) 'Will' would be used to ask for a prediction (e.g., Will I feel warmer?), not to make an offer. Options (b) and (c) are incorrect.

**Rule:** The Future Continuous Tense (will be + verb-ing) is used to describe an action that will be in progress at a specific time in the future. At 3 PM, the meeting will be ongoing. This is a common way to explain why one is unavailable. Option (a) 'will have' is a simple future statement but less specific about the ongoing nature of the event. Option (c) 'have' is simple present. Option (d) 'will have had' (Future Perfect) implies the meeting will be over by 3 PM, which contradicts the sentence's meaning.