Given a scientific passage and an answer, generate a question for the given answer.

Ex Input:
Passage: Some molecules, such as proteins, are too large to pass through the plasma membrane, regardless of their concentration inside and outside the cell. Very large molecules cross the plasma membrane with a different sort of help, called vesicle transport . Vesicle transport requires energy, so it is also a form of active transport. There are two types of vesicle transport: endocytosis and exocytosis. Both types are shown in Figure below and described below. Answer: active transport

Ex Output:
What type of transport is vesicle transport considered to be?

Ex Input:
Passage: An ideal engine, the most efficient theoretically possible, is called a Carnot Engine. Its efficiency is given by the following formula, where the temperatures are, respectively, the temperature of the exhaust environment and the temperature of the heat input, in Kelvins. In a Carnot engine heat is input and exhausted in isothermal cycles, and the efficiency is . In all real engines heat is lost to the environment, thus the ideal efficiency is never even close to being obtained. Answer: carnot engine

Ex Output:
What is the name of the the most efficient possible engine?

Ex Input:
Passage: Hearing loss due to loud sounds can be prevented by wearing hearing protectors. They reduce the amplitude of sound waves entering the ears. Answer: hearing protectors

Ex Output:
Wearing what will reduce the amplitude of sound waves entering the ears?