【单选题】Our planet is like a bit spaceship. Our atmosphere acts【51】a shield against harmful radiation and space debris.【52】holds the air and people on the spaceship,【53】everything doesn't float away. Each of ...
【简答题】Many children would start school hungry without breakfast clubs, teachers have claimed. A new survey suggests these clubs are the only way many students can get a meal before lessons. About 54% of the...