Only by seizing every possible_____ to practice can you possibly hope to improve your spoken English.
If people eat natural poisons by mistake, they ________ go to hospital without delay.
Before us lies the biggest room, ________with things like guns, dolls and old clothes.
The invention of artificial hearts marked a turning point in the battle heart disease.
—Thank you for your coffee. —But you________ it.
Lily seems to know a lot about Hong Kong, but she has never been there.