extent 的組合 ???

(1) "the extent to which" is an idiomatic expression, equivalent to the meaning of "how much".

The classification of leases is based on how much risks and rewards incidental to ownership of a leased asset lie with the lessor or the lessee.

Example from Oxford dictionary:
The book discusses the extent to which (= how much) family life has changed over the past 50 years.



In general, "to ... extent" is an idiom (or set phrase) used to show how far something is true or how great an effect it has. (definition from Oxford)

example-1: "to the extent that"
(a) = insofar as 在…的範圍内(程度上)
e.g. The shortage do not exist to the extent that (= in so far as) you report.
e.g. That's the truth to the extent that (= in so far as) I know.

(b) = so much 如此…以致於
e.g. Violence increased to the extent (= so much) that residents were afraid to leave their homes.

example-2: "to such extent that" 如此…以致於
e.g. He had changed to such an extent (= so much) that I no longer recognized him.



2012-10-16 10:47:55 補充：
All these expressions are adverbial, adding information to the main verbs.