Laura was speechless with rage. 

劳拉气得说不出话来。

have nothing to say

‘ I have nothing to say to you, ’ she said icily. 

“我对你没什么可说的。”她冷冷地说。

be lost for words

Every time you talk about a new subject for the first time, you will be lost for words.

每次你第一次谈论一个新的话题，你都会不知所措。

keep to yourself

Some things you keep to yourself. 

有些事情，你留在心底。