Ffl
abbr. federal firearms license 联邦轻武器许可证; fixed and flashing 固定并闪光
🗣️ 情景例句
I suggest that we go climb White Cloud Mountain tomorrow.
我建议明天一起去爬白云山。
To learn how to count
学习记账
The first records the arrival of longitudinal vibrations.
首先记录下的是纵向波的到达；