quaternaries

1.【地】第四纪[系]的

2.四个一组的;由四部份组成的;第四的

3.【化】四元的;四价的;季的;【数】四进制的

1.【地】第四纪

2.【数】四进制

3.四;四个一组的东西;第四组组成部分

1.the fourth member of a set

2.the current period of geologic time, beginning 1.6 million years ago and characterized by the appearance and dominance of humans

1.consisting of four parts, or occurring in sets of four

2.bonded to four other nonhydrogen atoms or groups of atoms, or containing atoms bonded in this way