Only by practising a few hours every day ________ be able to play the piano well.

________ you play chess—Yes, I can.

He _____in London for many years, but he has never regretted his final decision to move back to China

The job market is competitive. Therefore, you have to be _________ knowledge and skills in order to employed in the future.

下列各句中，没有语病的一句是（ ）