**Rule:** The Present Continuous Tense ('is/are' + verb-ing) is used for fixed future plans and arrangements, especially for scheduled events like sports matches. It indicates that the event is definitely happening. Option (a) is also possible for schedules, but (c) is very common. Option (b) is future perfect.

**Rule:** The 'be going to' future is used to make a prediction based on present evidence. The children's excitement is the current evidence that leads to the prediction about their future action (or intention) of waiting. Option (d) is a more general prediction, less connected to their current state.

**Rule:** This sentence requires the Future Continuous Tense. A common structure is 'will + still + be + verb-ing' to ask if a current action will continue in the future. The question asks about an action in progress ('working') at a specific future point ('in ten years' time'). Therefore, 'will still be' (followed by 'working') is correct. Option (c) would require a duration.

**Rule:** 'Be going to' is used to predict a future action based on present evidence. The fact that 'the children are very quiet' is the evidence that leads to the suspicion or prediction that they are about to do something mischievous. It's a conclusion drawn from the current situation. Option (a) would be a more general, less evidence-based prediction.

**Rule:** 'Be going to' can be used to talk about events that are already scheduled to take place. It indicates a future fact or a planned event. The present continuous ('is being') would also be possible, but 'is going to be' is a very common way to announce a scheduled future event. Options (b) and (c) are grammatically incorrect.

**Rule:** The Future Simple Passive ('will be' + past participle) is used to state a future fact or a planned outcome. 'will be completed' is the correct passive form. Option (d) 'will have been' would also fit, but 'will be' is a more direct and common way to state the future completion date.

**Rule:** The Simple Future with 'will' is used here to make a promise for a future action, decided at the moment of speaking. The speaker spontaneously decides to think and then inform. Option (d) would suggest a prior intention to think, which is less fitting for this context.

**Rule:** The Future Continuous Tense (will be + verb-ing) is used to talk about an action that will be in progress over a period of time in the future. The context implies that the act of studying will be ongoing during the time of the party. Option (a) 'will study' is a general future statement. Option (b) 'will have been studying' (Future Perfect Continuous) would require a duration (e.g., 'for three hours'). Option (d) 'study' is the simple present and incorrect for a future continuous action.

**Rule:** The Present Continuous Tense ('is/are' + verb-ing) can be used to talk about definite plans or arrangements for the future. Introducing new regulations is a planned government action. Option (a) 'introduces' would be used for a scheduled, repeated event, not a one-time plan. Options (c) and (d) are incorrect tenses.

**Rule:** This question tests tense consistency. The reason for the present situation ('We can't get a table') is a past action (or lack thereof). The failure to make a reservation happened in the past. Therefore, the Simple Past Tense ('didn't make') is required. The other options refer to the future, which doesn't explain the current problem.