These books are for students ____ mother language is not English.
Poor _____ it may be, there is no place like home, _____ you may go.
_____ hard she tries, she can hardly avoid making mistakes in her homework.
When you read the book, you' d better make a mark _____ you have any questions.
Helen listened carefully _____ she might discover exactly what she needed.
You may arrive in Beijing early _____ you mind taking the night train.