He is always serious ________ his work.

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The blouse doesn't look nice on ________.

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There ________ a pair of shoes under the bed. The shoes ________ mine.

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My father is in Shanghai ________ present.

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His parents ________ teachers.

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The young boy is good ________ me. He is good ________ English and often tells me oral practice is good ________ improving spoken English.

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The difficulty is ________ we haven't so many workers.

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Comrade Li is very strict ________ his child and ________ his work he does.

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She didn't work hard at her lessons so she failed ________ all the exams.

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--- Where were you just now?

--- At ________.

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