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(单选题)What is the difficulty confronting researchers of facial-rec (单选题)What is said to be a shortcoming of facial-recognition machi (单选题)What does the passage say about machine accuracy? (单选题)Why did researchers create MegaFace? (单选题)What is the key factor that eases student tutors’ learning? (单选题)What do we learn about Betty's Brain? (单选题)What are researchers rediscovering through their studies? (单选题)What has the past half century witnessed according to Kapsal (单选题)What will the Smithsonian Institution Archives do with the l (单选题)What is Darwin’s letter about?