The mercury(水银) had become what we now refer to as a superconductor(超导).
举一反三
- Now we can fly to Tokyo. There was a time ______ we had to take a boat. A: how B: what C: why D: when
- Now we can fly to Tokyo. There was a time _____ we had to take a boat. That was very inconvenient. A: then B: what C: why D: when
- You have no idea _____ then. A. what a hard time we had B. we had what a hard time C. what we had hard time D. what hard time we had
- Now we have _____ pigs as we had three years age.
- Now we can fly to Tokyo. There was a time ______ we had to take a boat.