那是书包 翻译成英语怎么说?是写That is a bag.还是That is bag.还是两种写法都对?

问题描述:

那是书包 翻译成英语怎么说?是写That is a bag.还是That is bag.还是两种写法都对?

应该加不定冠词a:
This is a bag.尽管你不强调“一个”,"a" 在此是必需的.