这张老照片背面没有日期，我们不知道是什么时候拍的。

The back of this old photo is ___dateless, so we don't know when it was taken.

周六晚上他独自在家看电视，因为没有约会对象。

He stayed home watching TV on Saturday night because he was ___dateless.

这些古老的格言因其永恒的智慧而历久弥新。

These ancient proverbs remain relevant due to their ___timeless wisdom.