portable nuclear reactor

例句：

1. 1. The portable radio is perfect for outdoor activities.
   便携式收音机非常适合户外活动。
2. 2. This portable charger can be used to recharge multiple devices.
   这个便携式充电器可以用于为多个设备充电。
3. 3. The portable calculator is useful for quick calculations on the go.
   便携式计算器在移动时非常方便进行快速计算。