What is the lecture mainly about？A．Various painting techniquesB．Ways to determine the purp

What is the main purpose of the lecture？A．To explain why scientists disagree about the age

What is the lecture mainly about？A．Oral traditions in folktales and fairy talesB．Common ch

What is the lecture mainly about？A．How astronomers found the correct interpretation for a

What is the lecture mainly about？A．Ways to limit the expansion of international tradeB．How

What is the lecture mainly about？A．Why some newspapers do not improve their servicesB．What

What aspect of the Earth 750 million years ago is the lecture mainly about？A．The changes i