barometer

爷爷的老式气压计显示明天可能会下雨。

Grandpa's antique ___barometer indicates rain might come tomorrow.

社交媒体上的讨论热度是公众情绪的重要晴雨表。

The buzz on social media serves as a key ___barometer of public sentiment.

股市常常被视为经济信心的晴雨表。

The stock market is often considered a ___barometer of economic confidence.