Which mineral has the properties of double refraction and it will react with acids to produce bubbles?

How many valence electrons does an atom need in order to be stable?

The ___________ of a mineral refers to how well the mineral reflects light. (type your answer in all lowercase letters)

. Select the correct description of the function .

In GIS, tools like Buffer, Clip, and Intersect are examples of _______ , which perform operations that create new datasets from existing data.

In “An improved coverage-oriented retrievalalgorithm for large-area remote sensing data” which implementation approach was found most suitable for very large target areas (e.g., Xinjiang), and why?

The function is defined as . Select the function definition that is equal to .

The function is defined as Select the set corresponding to the range of .

, and Select the correct statement about the inverse of .

Select the value of .