Why is the woman confused A: A website has been modified. B: A password is not working. C: An email has been deleted. D: A computer is malfunctioning.

词汇与结构Normally, pressurization problems are caused by a malfunctioning of the pressure outflow or the pressure regulating valves _______, which allows the air to escape out of the pressurized cabin.

What is the problem A: A leak has been found. B: There is some water damage. C: Some pipes need to be replaced. D: The plumbing system is malfunctioning.