Ye Shiwen is a _________ swimmer. She swims very _________.

More than one teacher _____ told him it is important that he learn English well if he _____ aboard

When did Kate’s grandma die—While the doctors______ on her

John isn’t here right now. He ______ Mr. Black’s office. Perhaps he______ in several minutes.

People often have this belief ______ developmentis bad for the environment, but this does not have to be true.