________ the job takes a significant amount of time, most students agree that the experience is worth it.

Tang Hai is chatting with his e-pal David on QQ (T: Tang Hai   D: David)
D: Hi. How is it going these days?
T: Pretty good! We celebrated our Dragon Boat Festival(端午节) last week.
D: Dragon Boat Festival?1
T: To remember an ancient Chinese poet(诗人)。
D: How do you usually celebrate it? 
T:2 But this year, we did something more interesting.
D: What did you do?
T: Our school had a Dragon Boat race.
D:3 who won the race?
T: Our class.
D:4
T: Thanks a lot. I hope you can come to China sometime.
D:5 I'm interested in Chinese traditions. Tell me more about them next time.
T: Ok, I will. See you.
D: See you!

某四棱锥三视图如图所示，则该四棱锥体积为（   ）

史称唐太宗时，有大臣奉请修复长城，唐太宗一笑置之。唐太宗不修长城的理由是（    ）