Franca's behaviour towards Edward leaves much to be desired. This means that Franca's behaviour was

Step 1: Analyze the question The sentence uses the idiom "leaves much to be desired" and asks what it means for Franca's behaviour.

Step 2: Explain the concept "Leaves much to be desired" means something is poor or not good enough. Many things could be improved, so it falls short of the expected standard. It is a polite way of saying something is bad or inadequate.

Step 3: Work through the options

• A. unsatisfactory: This means not good enough, which matches the idiom exactly.
• B. appreciated: This means valued or welcomed. It is a positive meaning, so it does not fit.
• C. commendable: This means praiseworthy. It is the opposite of the idiom's meaning.
• D. unexpected: This means surprising. The idiom is about quality, not surprise, so it does not fit.

Step 4: Answer Franca's behaviour towards Edward was unsatisfactory.

Tip: Learn idioms by whether they are positive or negative. "Leaves much to be desired" is negative, so you can eliminate B and C straight away, since both are positive. Then ask yourself whether the idiom is about quality or about surprise. Here it is about quality, so A is correct. Related expressions include "falls short of expectations" and "is below standard".