--- Have you ____ been to our town before? --- No, it’s the first time I ___ here.
―The weather is changeable here. Please take more clothes. ― _________.
The old lady who caught a bad cold complained that the doctor was ______ too much for the treatment given to her.
The international agreement, __________to help people kick off the habit of smoking, was signed two years ago.
The fact has worried the people across the world ___________ the earth is becoming warmer and warmer these years.
A college student had stayed up all night, _______ for his test the next day.