One example I can think of are amalgams of mercury. Mercury is normally liquid, but will mix with “solid” metals like silver or gold. In a similar way, mostly solid butter is often mixed with vegetable oils to get a soft spreadable mixture. read more
You can not really mix a solid and the liquid in the sense that you would get a mixture. Closest you can get is mud where the liquid, water, lubricates the sand so it moves easily creating mudslides. But that is not a mixture in the sense of the word. read more
Sand is an example of a mixture with different solid particles. Concrete is another example of solid mixture. A mixture is a combination of two different substances that do not chemically combine. Also, mixtures are substances with components that can be separated from the mixture. read more