单句改错 下列句子中各有一处错误,请指出并改正(每处限改一词). 1. Hundreds of people crowded in the church for the wedding. 2. There remain a certain doubt among the people as to the practical value of the project. 3. There is a real danger which the US will not keep its position on the world economic stage if the bad situation continues to go on. 4. Rather than to waste his time in chatting or playing games on the Internet, Bob borrowed lots of books to read in the summer holidays. 5. What she won the champion of the Winter Olympic Games made us excited. 6. If you want to study the nature of the universe, first of all, you must get hang of the origin of it. 7. It is required that every salesgirl should treat customers with a warm and friendly manner. 8. The children mustn't be tired----- they just have covered two miles. 9. Tom, you must make an apology to your mother. I won't have you speak to her like that. 10. The children watched amazing as the fireworks set off and formed all kinds of beautiful designs in the sky.