[A] that [C] when
[B] where [D] as

单项选择题[A] escape [C] dry[B] drain [D] leak

单项选择题Which of the following best summarizes the main idea of the passage

单项选择题According to the author, music notation is important because _________.

单项选择题It can be learned from this passage that _________.

单项选择题Research into the material culture of a nation is of great importance because _________.