Answer:
Nickel and penny.
Explanation:
The given pattern is
half dollar, quarter, dime...
This is a part of the pattern of US coins.
The pattern of US coins in decreasing order is
Dollar, half dollar, quarter, dime, nickel, penny.
It is clear that the next 2 words in this pattern after dime are nickel and penny.
Therefore, the required 2 words are nickel and penny.