Question

track-and-field events have been very popular for a long time.
have been very
for a long time
been very popular
have been

Explanation:

The task is to identify the verb phrase from the given sentence. The core verb phrase in "Track-and-field events have been very popular for a long time" is the part that conveys the state of being popular, which is "have been very popular".

Answer:

been very popular