1.In each of the following groups of words, there are four underlined letters or letter combinations marked A, B, C and D. Compare the underlined parts and identify the one that is different from the others in pronunciation.
A、game
B、late
C、trade
D、have
What is the main idea of the passage?
A、Exercise strengthens people's body
B、Exercise helps babies to grow.
C、Exercise improves people' s lif
D、Exercise benefits the brain.
What is the writer's tone in introducing the AIDA model?