retractable [rɪˈtræktəbl:]

例句:

• A 20,000-seat arena with a retractable roof is planned.
  一个有两万个座位、带可开合顶棚的体育场正在规划中。
  
• a knife with a retractable blade
  弹簧刀
  
• So, any thoughts of what you want for the retractable bed kid?
  那么想为那个睡折叠床的小子做 什么 ?
  
• The roof also needs an even bigger extension as it would now need to cover the running track and the retractable seats on it.
  来自BBC
• The main reason is the decision to add retractable seating to bring football fans closer to the action.
  来自BBC
• There may be sudden narrowing or phimosis of a previously retractable foreskin, blocking the flow of urine.
  来自BBC