Landslides occur when earth materials that are no longer held by friction move down a slope with the of gravity. i think this is true. but i really need be because this may be wrong. i'm offering 11 points and marking the best answer as brainliest. don not just answer for the points because i am very smart and can answer any question anyone has but if you give me a wrong answer, then you won't get marked brainliest.

Yes, the given statement is true.  

A landslide is illustrated as the movement of debris, the mass of rock, or earth down a slope. The landslides are a kind of mass wasting that signifies any down-slope movement of rock and soil under the direct effect of gravity.  

The slope movement takes place when the forces functioning on down-slope primarily because of gravity exceeds the strength of the Earth substances, which compose the slope. The causes comprise elements, which elevates the influences of down-slope forces and factors, which contribute to reduced or low strength.  

a.) a destruction fo cells by viral reproduction

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.