| | | | | | | | | | | | | 250 400 | | | | | | | | | | B2 C | | | ① | ② | ③ | ④ | ⑤ | ⑥ | ⑦ | | ⑧ | 300-500 6 1 | | | | | | C B | | | | C | | | | | | | | | | | 200-400 4 8 | | | | | | | | | |