import pandas as pd
from sklearn.linear_model import LinearRegression

data = pd.DataFrame({
    'A': [1, 2, 3],
    'B': ['a', 'b', 'c'],
    'C': [0.1, 0.2, 0.3],
    'D': [True, False, True]
})

X = data.iloc[:, [0, 2]]
y = data.iloc[:, 3]

model = LinearRegression()
model.fit(X, y)