听下面一段独白，并按要求在试卷上完成任务，你可以边完成任务。然后你会看到五个问题和相关的选项。请从每个问题A、B、C三个选项中选出最佳选项。 1. How many letters are you asked to put into the circle? [     ] A. 5 B. 6 C. 7 2. There are three letters left, which circle should they be put into? [     ] A. B-7,  D-2,  G-6 B. B-6,  D-7,  G-2 C. B-2,  D-6,  G-7 3. The sum from each line and each crossing is . [     ] A. 28 B. 30 C. 32 4. What will happen if we put the letter F into the circle 5? [     ] A. We can't solve the problem. B. We can solve the problem. C. Nothing will happen. 5. The problem we have solved is about . [     ] A. math B. science C. history