1 . It is not until spring came ___________ the trees started to blossom. (用适当的词填空)

2 . It is due to the lack of job experiences ______ many college graduates are turned down in the job market. (用适当的词填空)

3 . It is for the future generation _______ we should protect our current environment. (用适当的词填空)

4 . It was his carelessness _________ caused his failure this time. (用适当的词填空)

5 . Was it at the school ________ he spent his childhood? (用适当的词填空)

6 . Remember, whenever you travel abroad, it is your country _______ you are representing. (用适当的词填空)

7 . It was in the dinning hall ______I met my first friend in senior high school. (用适当的词填空)

8 . I have to say it is through failures ________ I have learned so much, which builds up my confidence. (用适当的词填空)

9 . It is in the city you are going to pay a visit to ________this kind of beer is produced. (用适当的词填空)

10 . It was the trust of their leader ________ motivated them to work hard and efficiently.(用适当的词填空)