一时间我什么也说不出来，只能站在那儿看着。

For a moment I could say nothing. I could only stand and look.

《柯林斯英汉双解大词典》

因为他一时找不到，就说：“我知道你在那儿，你最好自己出来！”

As he could not find it immediately, he said: "I know you are there, so you had better come out!"

youdao

那只夜莺跳出来了，它唱得那么好听，他们一时还想不出什么话来说它不好。

The nightingale came forth and sang so delightfully that at first no one could say anything ill-humored of her.

youdao

Alums with Nobel prizes? Oh, I don't... I can't think of any like, off the top of my head.

获得诺贝尔奖的校友吗？这个……我一时还想不出来。

知道约翰·纳什吗？ - SpeakingMax英语口语达人

It's really hard to think of all stuff off the top of my head.

脑子里一时想到的都说出来还真难呢。

只要是音乐就好 - SpeakingMax英语口语达人