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填空題

It may be necessary to stop（）(每隔一定時間) in the learning process and go back to the difficult points in the lessons.

答案： at intervals

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There’s a man at the reception desk who seems very angry and I think he means（）(想找麻煩).

答案： to make trouble

We’d like （）(預訂一張餐桌) five for dinner this evening.

答案： to reserve a table for