【題目】_____in the sports world，a sportsman needs to train constantly to keep himself in best condition．

【題目】The twins were so much alike that we had great trouble ________one from the other.

【題目】______ catch the first bus, he got up very early this morning.

【題目】From 1902 to 1904, Picasso painted a series of pictures________ the main color was blue.

【題目】Neither the headmaster nor the teachers _____ take a vacation next week.

【題目】We stopped _________, but there was not any sound.

【題目】How would you feel being locked in the house all day with no one for _______?

【題目】He found it increasingly difficult to read,________ his eyesight was beginning to fail.

【題目】—Excuse me, madam. Could you please tell me _________ the bus arrives?

【題目】I have an appointment _______ Dr．Brown，but I need to change it．