When he is free, he often helps his parents ________ some housework.
Don’t ________ your exams. They are very easy.
---Do you think people can live on the moon one day? ---May be. However, it may take ________ years to make it.
Ask your brother to call me if he ______ back tomorrow.
--Would you please tell me________this DV? --Yes.It’s very easy.
Jack’s mother wondered_________.