The correct line where all the compound adjectives are written correctly is:
3. Good-looking, easy-going, ten-pound, brand-new, part-time, first-class, well-known, north-east, short-sleeved, badly-written, left-handed, second-hand.
This line contains properly formed compound adjectives. For example:
- "ten-pound" refers to an amount of weight.
- "first-class" denotes the highest quality.
- "left-handed" indicates the use of the left hand.
- "second-hand" describes something used or previously owned.
The other options include incorrect combinations like "ten-class" and "first-pound," which are not recognized compound adjectives.