The United States Geological Survey (USGS) said
Sunday the island had experienced more than 500 earthquakes—13 with a magnitude greater than 4.0—in the 24 hours following the 6.9-magnitude quake.
The concern for residents continues to be the lava and
gas emitted from vents, though.
官方译文：居民目前担忧的还是火山口喷出的岩浆和气体。
The concern for residents是“对居民的担忧”，怎么成“居民的担忧”？
