29. With so much work to do, I don’t think I’ll be able to come to your party tonight, but I’ll certainly invite you to dinner ________ next week. (A) some time (B) sometime (C) sometimes (D) some times

31. Why did the researchers say eggs came after the chicken? (A) Because one of the egg-forming ingredients comes only from the chicken. (B) Because eggshell could be used to make a lot of products. (C) Because eggs are much lighter than the chicken. (D) Because they are British researchers.