Gravity bomb

A gravity bomb is an aircraft-delivered bomb that does not contain a guidance system and hence follows a ballistic trajectory.This described all aircraft bombs until the latter half of World War II and the vast majority until the late 1980s.
Then, with the dramatically increased use of precision guided munitions, a new term was needed to separate 'smart bombs' from those that weren't. Dumb bomb was used for a time, but many in military circles felt it sounded too trite, and eventually 'gravity bomb' gained currency. Previously they were also referred to as Iron bombs.
Special types of gravity bombs include retarded gravity bombs, which use a mechanical method of creating increased drag, such as a parachute, ballute or drag-inducing petals. These deploy after the bomb is released and slow its fall, giving the aircraft time to get clear of the blast zone when bombing from low altitude.

Dabbling ducks

The dabbling ducks are a group of eight genera and about 55 species of ducks, including some of the most familiar Northern Hemisphere species. They are in the duck, goose and swan family Anatidae. The latter article should be referred to for an overview of this very large family. The dabbling ducks, together with the diving ducks make up the sub-family Anatinae.
This group of ducks is so named because its members feed mainly on vegetable matter by upending on the water surface, or grazing, and only rarely dive. These are mostly gregarious ducks of freshwater or estuaries. These birds are strong fliers and northern species are highly migratory. Compared to other types of duck, their legs are placed more towards the centre of their bodies. They walk well on land, and some species feed terrestrially.
The Marbled Duck Marmaronetta angustirostris, which used to be included among the dabbling ducks, is now classed as a diving duck.