Practice
【例1】（2009浙江）
The trip to that city was eye-opening for everyone, and near its end, all the young people in our group began to reflect on what it had meant. …But what we actually saw simply 23 us all – the rundown houses, the children in rags, the people begging for money …
Twenty years later, the 43 could guess what the professor had in mind. He 44 himself, perhaps, as inviting his students to start an exciting 45 into an unknown world invisible(无形的) to the 46 , which can be discovered only through scientific 47 . But the seventeen-year-old girl could not accept or even 48 the invitation. She was just 49 to understand the world. And she 50 that her firsthand experience could be the 51 . The professor, however, said that it was 52 . He was taking away her only 53 for knowing and was providing her with no substitute(替代). “I remember feeling small and 54 .” The woman says, “and I did the only thing I could do. I 55 the course the afternoon, and I haven’t gone near science since.”
