Thank you, Tamguatlay!
Is it because of the relations between "begin" and "end"? (like "eat or drink"?) Or is it due to 1 word "will" can be applied for the 2 verbs in the sentence connected by "and", i.e. "begin xx and end xx"?
How about "They will go to the zoo and have lunch there"? "They will go to the zoo and will have lunch there"?