Why, for instance, do water users in a megacity like Lagos not pay an extra charge to get cesspits pumped out?

Combining the construction practice of Shantou port Guang ao Phase I Project, this paper introduces a new technology of transporting caissons by gas-bags.

The surface of Mars shows a wide range of geologic features, including huge volcanoes—the largest known in the solar system—and extensive impact cratering.