The ecosystems生态系统of the Earth provide a vast array of free public services that are essential for the support of civilizations.

42. And how
当然罗!
W: The concert pianist was fantastic.
M: And how!

43. appeal to
受…欢迎
Nylon brushes appeal to many people because they are inexpensive and they produce an acceptable effect on paper.

44. apply for
请求, 申请
The man will have to apply for his birth certificate in writing.

45. apply sth to somewhere
He could apply the techniques to应用于 principles of composition, color and design.

46. apply to
use for

47. around the corner
The theater’s just around the corner.

48. as a rule
In general; for the most part
I didn’t care much for喜欢 horror movies as a rule.

49. as good as
M: Excuse me, could you tell me how to get to the post office?
W: Your guess is as good as mine. I’m new around here.

50. as long as
Some friends of my parents’ live out there. And they invited me for as long as I wanted to stay.