A formal contract is signed which is renewable annually.正式签订了每年可续签的合同。Seven million doses of vaccine are annually given to British children.英国孩子每年要接种7百万剂疫苗。El Salvador produces 100,000 tons of refined copper annually.萨尔瓦...
Each morning cleaners make sure everything is spotless.每天早晨，清洁工们会把一切都打扫得干干净净。Vacuum cleaners work by suction.真空吸尘器靠抽吸除尘。He travels in vacuum cleaners.他到各地推销吸尘器....