pref.表示“第一的,主要的”之义;
例句:
He tapped the side of his nose in an uncharacteristically arch gesture.
他轻叩鼻侧,做了个不常见的调皮手势。
The bridge had seven arches.
这座桥有七个拱洞。
The cat arched its back.
猫拱了拱腰。