While ______ a tunnel through the mountain, the workers discovered an underground lake.
A: built
B: to built
C: being built
D: building
A: built
B: to built
C: being built
D: building
举一反三
- While building a tunnel through the mountain, ________. A: an underground lake was discovered B: there was an underground lake discovered C: a lake was discovered underground D: the workers discovered an underground lake
- The underground connection ___ when I moved into the house. A: is still being built B: was still being built C: was still building
- The building ______ at this moment will be a modern hospital. A: built B: being built C: to be built D: building
- The building ______ over there will be the largest laboratory in our university. A: be built B: being built C: built D: is being built
- Look ! The building ________ now is our teaching building . A: being built B: built C: to be built D: building