[lowatt]

Authors may be "language pros" but the content can use more proof reading. One (trivial) example:

> Kanji are ideograms imported lock, stock, and barrel from __mainland Asia__ into Japan over hundreds of years, starting around the 5th century, followed by Buddhism in the 6th century.

"mainland Asia"? This makes me laugh. Technically not totally wrong, but, do people really say that? Won't people from India get offended? If someone (e.g, a child) googles "mainland Asia", the first result is Indochina. Did Japan import Chinese characters from Indochina in the 5th century? I believe a textbook should be clear, straightforward, and shouldn't obscure/blur facts.

[BossingAround]

To me, the biggest problem with the sentence is "lock, stock, and barrel," which won't be understandable to a number of non-native speakers.

I don't know who the target audience is, but not having non-native speakers in mind seems like a pretty big oversight to me.

Mainland Asia is, of course, pretty bad as well.

[hurflmurfl]

As a non-native speaker, I don't think I've ever seen this expression, but one can easily guess what it means. Enumerating bits of the whole as a way to emphasize the wholeness, I think, might be common in many languages.

Regarding mainland Asia, I just understand it as "not island" Asia.

[hombre_fatal]

I don’t think I’ve ever heard the expression outside of the title of that one movie.

[solarmist]

I've heard and even used it a couple of times, but it's not very common anymore.