Answer :
The correct choice for the blanks in the sentence "I am looking for ___ lettuce, a ___ tomatoes, and ___ butter" is option C: "a head of; a kilo of; a box of".
Here's a breakdown of each part:
A head of lettuce: Lettuce is often sold in forms called 'heads'. This refers to a whole lettuce, like a head of romaine or iceberg lettuce.
A kilo of tomatoes: Tomatoes can be measured by weight, and 'kilo' refers to a kilogram, which is a common unit of measurement in many countries.
A box of butter: Butter is frequently sold in boxes, especially in units such as sticks or packs.
Understanding these units is helpful when learning English, especially when discussing groceries or cooking.