Necessitating
v. 使…成为必要, 需要( necessitate的现在分词 )
🗣️ 情景例句
Do you hike or fish on your trips?
旅游时，你会步行或钓鱼吗？
The doctor said I looked run down.
医生说我看起来身体渐渐差了。
Once the existence of this wave-length had been discovered,
一旦这种波长的实际存在被发现，