We wrote to them last week and ____________ them to reply in the next few days.

The correct completion for the sentence is "asked." Therefore, the sentence reads: "We wrote to them last week and asked them to reply in the next few days."

In this context, "asked" is a verb that indicates a request or inquiry made to another party. The structure of the sentence follows a past tense narrative. The use of "last week" suggests that the action of writing occurred in the past, and thus it is logical to follow it with another past tense verb ("asked") that maintains the time consistency in the sentence. This construction implies that a proactive effort was made to elicit a response, underscoring the communication's urgency or importance.