Comprehension:
In the following passage, some words have been deleted. Read the passage carefully and select the most appropriate option to fill in each blank.
natural products blossomed into still a valuable Traditional medicines (TMs) make (1) natural products and are of great importance. Such forms of medicine as traditional Chinese medicine (TCM), Ayurveda, Kampo, traditional Korean medicine (TKM), and Unani (2) and have been (3) all over the world for hundreds or even thousands of years, and they (4) orderly-regulated systems of medicine. In their various forms, they may have certain defects, but they (5) repository of human knowledge. Select the most appropriate option to fill in blank number 4.
