那些在会议上故意提出争议问题的人总是激怒他人的挑衅者。

Those who deliberately raise controversial questions in meetings are always ___provokers who anger others.

花粉是春季常见的过敏原，会引发打喷嚏和流眼泪。

Pollen is a common seasonal ___provoker of sneezing and watery eyes.