The Roads of Dhaka are wider _____ (Fill in the gap)

The correct phrase to fill in the gap is "than those of Jamalpur."

So, the complete sentence is:

"The roads of Dhaka are wider than those of Jamalpur."

Explanation:

• "Than those of Jamalpur" is the correct choice because it compares "the roads of Dhaka" with "the roads of Jamalpur," using "those of" to refer back to the roads in Jamalpur.

Here's why the other options are less appropriate:

• "Then Jamalpur": This option does not fit grammatically for comparisons.
• "Than Jamalpur": This is incomplete because it does not specify what aspect of Jamalpur is being compared.
• "Than those at Jamalpur": This is also a valid option, but "than those of Jamalpur" is more precise and commonly used for comparing specific attributes like roads.

So, "than those of Jamalpur" is the most accurate and idiomatic choice.