On the first day of class, Mr. Whiteson gave us a lecture about a creature  called cattytiger, a kind of cat-like animal that completely disappeared during the Ice Age. He passed round a skull   as he talked, and we all felt interested and took notes while listening. Later, we had a test about that. When he returned my paper, I was very, very surprised. There was a very large cross through each of my answers. And so it was with everyone else's in our class. What had happened? Everyone was wondering and couldn't wait to get the answer. Very simple, Mr. Whiteson explained. He had made up all that story about the cattytiger. There had never been such an animal. So why none of us noticed that and how could we expect good marks for the incorrect answers? Needless to say, we got very angry. What kind of teacher was this? We should have guessed it out, Mr. Whiteson said. After all, at the very moment he was passing around the cattytiger skull (in fact, a cat's), hadn't he been telling us that it completely disappeared during the Ice Age? Clearly he was telling a lie. But we just kept busy making notes and none used his head. We should learn something from this. Teachers and textbooks are not always correct. We didn't find out it was a lie for   _  .
we simply believed our teacher very much we took notes carelessly we hadn't watched the skull carefully enough Mr. Whiteson spoke too fast