original: The core may be composed of solid and liquid layers, while the cores of Mars and Venus are thought to be completely solid as they lack an internally generated magnetic field.
simplifications: The core maybe made of solids and liquids. At the same time cores of Mars and Venus are believed to be pure solid because they don't have magnetic field. The center could have solid and liquid layers. The center of Mars and Venus might be solidified. They don't have a generated magnetic field inside. The core may be made of solid and liquid layers. Meanwhile, the cores of Mars and Venus could be completely solid as they don't have an internally generated magnetic field. The core may be made of solid and liquid layers. The cores of Mars and Venus are thought completely solid because they don't have an internally made magnetic field. The core could be composed of solid and liquid layers, the cores of Mars and Venus are solid as they lack an internally generated magnetic field. The core may be made up of solid and liquid layers. Mars and Venus's cores are believed to be completely solid. Mars and Venus are thought to have solid cores because they lack internal generated magnetic fields, while another is thought to be both solid and liquid. The core may be composed of solid and liquid layers. The cores of Mars and Venus are thought to be solid because they lack an internally generated magnetic field. Core are usually composed of solid and liquid layers but cores of Mars and Venus are thought to be completely solid as they lack an internally generated magnetic field. Planet cores can be solid or liquid, but the cores of Mars & Venus are thought to be solid because they do not have magnetic fields in them.