“The child’s life is not in danger any more，”the doctor said ________.[ ]

You will never gain success________ you are fully devoted to your work.

You ought to be stricter _____ your son; it’s no use only being strict _____ his work

Mary is hard-working. She works harder thanclassmates in her class.

Many clothing manufacturers now substituteartificial silk _____ natural silk to cut down costs of production