No less an authority than Walter Cronkite has reported that half of all Americans never read a book.

要想正确翻译这句话，必须要了解短语 no less.. than的用法。请看这个短语的主要用法如下：

1. no less than +基数词, 表达"多达...."“至少”

No less than 5 million people have contracted Covid-19.

有多达500万人都已经感染了新冠病毒。

Briefly, no less than nine of our agents have passed information to us.

总而言之，至少有9名特工向我们传递了情报。

He is lined up for no less than four US television interviews.

多达4家美国电视媒体排期邀请他上节目接受采访。

No less than 35 per cent of the country is protected in the form of parks and nature sanctuaries

该国多达35%的地区以公园和自然保护区的形式受到保护。

2. no less than +名词，表达"简直是....不亚于..."

It is no less than a murder to batter the girls like that.

这样打人简直就是在谋杀。

3. no less +形容词+than ..,表达“不比...差，和...一样都..”

She's no less capable than the others.

她的能力并不比别人弱。

Huawei is no less expensive than iPhone.

华为手机不会比苹果更不贵=华为和苹果手机都挺贵的。

试比较：

Huawei is no more welcomed than iPhone.

华为手机没有比苹果更受欢迎=华为和苹果手机都不受欢迎。

翻译小技巧：

no less...than：二者都....

no more...than：二者都不...

4. no less +a person/thing+than xxx: 表达强调和惊讶、惊奇、赞赏等，有时则含有讽刺意味! “亲自”，“正式…本人…”“竟然”等

The meeting was attended by no less a person than the President of the United States.

美国总统亲自出席会议。（出席会议的人竟然是美国总统本人。）

No less a person than Zhoujielun will come to our school.

不是别人竟是周杰伦要来我们学校。

We hope to invite no less a person than an assistant professor.

我们想聘请的正是一位助理教授。

She spoke on no less a subject than the future of the human race.

她竟谈论起人类的未来这个题目来了。

The writer is no less a person than a prince.

那位作家竟是一位亲王。

It will be a grand occasion. No less a person than the Queen herself will perform the opening ceremony.

这将是盛大的场面，女王将亲自主持开幕式。

单独使用的no less也具有此种含义：

She's having lunch with the Director, no less.

她居然在与主管一起进午餐。

He had returned to England in an aircraft carrier no less

他竟然坐航空母舰回的英格兰。

Good heavens! It's the President himself, no less!

老天！那是总统他本人，一点不假！

所以：上述句子可以译为：

No less an authority than Walter Cronkite has reported that half of all Americans never read a book.

正如权威人士沃尔特·克朗凯特（Walter Cronkite）所报道的那样，有一半的美国人从未读过书。