So typically, it follows the pattern of a b a c b c.

所以它遵循 a b a c b c 的模式。

Read the four choices marked A B C and D. Choose the best answer and mark the letter of your choice on the answer sheet.

阅读标有A B C和D的四个选项，选择最佳答案并在答题纸上标记您选择的字母。