问:

that能否省略?

答:
可以,that可以省略。
一般来说,在以下几种情况下可以省略that:
1. 在定冠词the的后面
比如:
I think (that) the man is nice.
She said (that) the car is expensive.
2. 在名词短语的后面
比如:
I believe (that) her explanation is reasonable.
They doubt (that) my story is true.
3. 在形容词短语的后面
比如:
I'm glad (that) you're all right.
She's angry (that) he left without telling her.
4. 在最高级短语的后面
比如:
I'm happiest (that) you passed the exam.
She's most upset (that) you forgot her birthday.
5. 在情态动词的后面
比如:
She must (that) he went to work early.
You should (that) she knows about this.
6. 在表示疑问的句子中
比如:
Do you wonder (that) he hasn't shown up yet?
Did you think (that) I wouldn't notice?
总的来说,在the,名词短语,形容词短语,最高级短语,情态动词以及表示疑问的句子后,可以省略that,不影响句子的语法正确性。
省略that可以使句子更简练。但是在需要强调或突出时,也可以添加that,以清晰表达思想。
希望以上回答能够满足您的需求。若还有任何疑问,欢迎随时提问。