Fossilized spores suggest that higher plants (embryophytes) have lived on land for at least 475 million years. Early land plants reproduced sexually with flagellated, swimming sperm, like the green algae from which they evolved. An adaptation to terrestrialization was the development of upright meiosporangia for dispersal by spores to new habitats. This feature is lacking in the descendants of their nearest algal relatives, the Charophycean green algae. A later terrestrial adaptation took place with retention of the delicate, avascular sexual stage, the gametophyte, within the tissues of the vascular sporophyte. This occurred by spore germination within sporangia rather than spore release, as in non-seed plants. A current example of how this might have happened can be seen in the precocious spore germination in Selaginella, the spike-moss. The result for the ancestors of angiosperms was enclosing them in a case, the seed. The first seed bearing plants, like the ginkgo, and conifers (such as pines and firs), did not produce flowers. The pollen grains (males) of Ginkgo and cycads produce a pair of flagellated, mobile sperm cells that "swim" down the developing pollen tube to the female and her eggs.
What is the common name for Selaginella?
the spike-moss

The United States Army (USA) is the largest branch of the United States Armed Forces and performs land-based military operations. It is one of the seven uniformed services of the United States and is designated as the Army of the United States in the United States Constitution, Article 2, Section 2, Clause 1 and United States Code, Title 10, Subtitle B, Chapter 301, Section 3001. As the largest and senior branch of the U.S. military, the modern U.S. Army has its roots in the Continental Army, which was formed (14 June 1775) to fight the American Revolutionary War (1775–83)—before the U.S. was established as a country. After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784, to replace the disbanded Continental Army. The United States Army considers itself descended from the Continental Army, and dates its institutional inception from the origin of that armed force in 1775.
What date was the U.S. Army created?
3 June 1784

The American professor Robert H. Goddard had worked on developing solid-fuel rockets since 1914, and demonstrated a light battlefield rocket to the US Army Signal Corps only five days before the signing of the armistice that ended World War I. He also started developing liquid-fueled rockets in 1921; yet he had not been taken seriously by the public, and was not sponsored by the government as part of the post-WW II rocket development effort. Von Braun, himself inspired by Goddard's work, was bemused by this when debriefed by his American handlers, asking them, "Why didn't you just ask Dr. Goddard?"[citation needed]
What professor began working on solid-fuel rockets since 1914?
Robert H. Goddard