Faculative
a. 允许的, 任意的, 兼性的, 偶发的
🗣️ 情景例句
We're not?
不在这里？
Why did you get home so late?
为什么你这么晚回家？
It soon became clear that the straight part of the dance changed when the sun's position changed. If the feeding place was toward the sun, the dancer headed straight upward during the straight part of the wagging dance.
情况很快就弄清了，舞蹈的直线部分是随着太阳位置的变化而变化的。