The bill must be paid immediately, or the electricity will be turned off.
Correct
The dress did not cost too much, but the quality it seemed excellent
Incorrect
The book was not long, but it difficult to read
Incorrect, no second verb
The material has been cut, and the pieces have been sewn together
Correct
After the plane circled the airport, it landed on the main runway.
Correct
The registration process took many hours since the line so long
Incorrect, no second verb
This type of medicine can be helpful, it can also have some bad side effects
Incorrect, no connector
we need to get a new car whether is on sale or not
Incorrect, no second subject
The waves were extremely high when the storm hit the coastal town
Correct
