通过键盘输入一个人的身高和体重，以英文逗号隔开，在屏幕上显示输出这个人的身体质量指数(BMI)，BMI的计算公式是BMI=体重(kg)/身高2 (m²) 。

Sure, to calculate the Body Mass Index (BMI) using a user's input for height and weight in English format (feet and inches for height and pounds for weight), you can follow these steps:

1. Prompt the user to enter their height in feet, inches, and their weight in pounds.
2. Convert the height from feet and inches to meters. One foot is approximately 0.3048 meters and one inch is 0.0254 meters.
3. Multiply the height by itself to get the square of height in meters squared.
4. Divide the weight in pounds by the height squared to get the BMI.

Here's a simple Python code snippet that demonstrates this calculation:

# User input
height_feet = float(input("Enter your height in feet: "))
height_inches = float(input("Enter your height in inches: "))
weight_pounds = float(input("Enter your weight in pounds: "))

# Height conversion
height_meters = height_feet * 0.3048 + height_inches * 0.0254

# BMI calculation
bmi = weight_pounds / (height_meters ** 2)

# Display the result
print(f"Your BMI is: {bmi:.2f}")