We could see seals swimming near the shore.
After leaving the Orkney Islands, we went by boat to [the] Shetland Islands, because we wanted to observe the gr[a]y seals with their pups that were [o]n the northwest coast. (First Certificate in English; B2; Spanish)
She sealed the jars so the jam wouldn't spoil.
In Egypt, [the] Pyramids are being sealed, because the perspiration of the tourists was ruining the paintings on the walls. (Certificate of Proficiency in English; C2; Portuguese)
to seal an envelope
Jenny, my girlfriend, told me that she sealed the envelope with trembling fingers and then posted it. (Certificate of Proficiency in English; C2; Spanish)
Police immediately sealed off the streets.
The police sealed off the main street a few weeks ago because they have been building a new restaurant. (Certificate of Proficiency in English; C2; German)