In this section, you will hear several passages. Listen to the passages carefully and then answer the questions that follow. Questions 11 to 13 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions. Now, listen to the passage. How did Shatiney imitate the silkworm
A．By squeezing liquid through small holes. B．By threading leaves together. C．By varying his diet. D．By extracting fibers from tree roots.