每日口說挑戰 答案卡一定要用 HB 鉛筆？

今日挑戰句子

Those machines had light-sensing devices called phototubes, and if they did not detect light in a certain spot, they recorded it as an answer.

那些機器裡有叫做光電管的光感測設備，如果在某個點沒有偵測到光，它就會被記錄為答案。