◎◎◎ concern ⪢⪢
_____ is a feeling of worry.
http://qindex.info/i.php?x=13676

○○○ hypersonic ⪢⪢
U.S. officials now believe the objects are mostly likely not secret U.S. technology but they worry they could be advanced systems by another country, potentially Russia or China, both known to test hypersonic systems.
http://qindex.info/i.php?x=15561

○○○ give in ⪢⪢
The wife refused to eat anything and began to look pale. Worrying about her health, as well as the baby's, the husband finally gave in.
http://qindex.info/i.php?x=16322

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