Which of the following is the correct description of the standard normal distribution? (Multiple choice)

For a pixel P with coordinates (x, y), P has four diagonally adjacent pixels, called diagonal neighbors. Which of the following can correctly represent the coordinates of the diagonal neighbors?

Which of the following sklearn.feature_extraction.text modules implements the tf_idf function? (Multiple choice)

Which of the following is the correct description of the properties of the probability density function? (Multiple choice)

Markov chain refers to a discrete event random process with Markov properties in mathematics.