R級的英文：
restricted (under 17 requires accompanying parent or adult guardian)（限制級，17歲以下觀眾要求有父母或成人陪同觀看）

• A restriction against smoking in schools.
  禁止在學(xué)校吸煙。
• Restricted access, development,potential
  受限制的接觸、發(fā)展、潛力
• One that restricts or modifies another; a qualification.
  資格限制或改變其它事件的事件；限定條件

• Under the hammer
  被拍賣
• under the ground;swam under water.
  在地下；游到水下
• Under water, famine; under snow, bread.
  洪水造饑饉，瑞雪兆豐年

• Is the requirement compulsory?
  必須按這個需求做嗎？
• In practice, this will often require a prioritization of your job requirements.
  實務(wù)上，這往往需要重新調(diào)整工作的優(yōu)先順序。
• All systems requiring accurate timing will require a crystal.
  所有需要精確定時的系統(tǒng)都要用晶體。