cover a year的用法和樣例：
例句
- In a year,your share of the solid waste amounts to nearly one metric ton.
一年內你所丟棄的那份固體廢料幾乎達一公噸。 - It then took up to 7 a year for the piglet cells to mature and start producing full quantities of insulin.
這些小豬細胞此後需要多達一年的時間發育成熟，並開始產生足量的胰島素。 - The construction of this canal took one year.
這條運河歷時一年才修建成功。 - This company spent a year developing this card punching system buses.
這家公司歷時一年才開發出這套公共車刷卡系統。
