一句翻译 机器闪

He must hide somewhere, since nobody could find him then.

He must hide somewhere,otherwise,he will be found.

He must hide somewhere,otherwise,he would be found at that time.

He must be somewhere,otherwise nobody found him then.

他一定是躲在什么地方了，要不然当时怎么没人找到他。
He must hide somewhere, since nobody could find him then.