Among the more than 100 problems to be tackled by the ‘Problem Study Society,’ founded in 1919, is the following:

36. The problem of drilling traffic tunnels under the Bering Sea, the English Channel, and the Straits of Gibraltar.

Faced with issue of exactly how one was to study this problem, Article V of the statutes of the society (authored by Mao) makes this observation:

In studying problems, those that require on-the-spot investigation should be studied on the spot, and those that do not require on-the-spot investigation, or for which on-the-spot investigation is presently impossible, may be studied from books, magazines, and newspapers, as for example the problem of Confucius and that of the three underwater traffic tunnels.

Mao’s Road to Power, vol. 1, pp. 410 and 412.