import re


def bytes_to_ascii(binary_blob: bytes) -> str:
    """
    Convert bytes to ASCII string, replace invalid symbols with "?".

    Args:
        binary_blob: Input bytes.

    Returns:
        Decoded ASCII string.
    """
    binary_blob = re.sub(rb"[^\x20-\x7E]", b"?", binary_blob)
    return binary_blob.decode("ascii")