3.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、useless
B、endless
C、unless
D、hopeless
There are numerous websites on the Internet ____ you can learn how to cook.
A、that
B、when
C、where
D、which
Pets____constant care are not suitable for people with little spare time.