The medicine ___ as soon as you take it. But it ____ the blood.
______ to sunlight for too much time will do harm to one’s skin.
It’s a difficult skill to master, but ______, it will benefit you for the rest of your life.
My grandmother has kept the photo ______ she can see it every day for a couple of decades.
Bob is in a hopeless situation, ______ we will keep a very close eye on.
In the past decades, sea ice ______ in the Arctic as a result of global warming.