Mr. Johnson starts to work very early in the morning and goes on working until late in the afternoon ________a break at midday.

　　A. with　　　　 B. for　C. as　　　　　　 D. through

________ born in Chicago, he was brought up in Italy.

A. Although B. Since　 C. As　 D. When

The reason for helping the man is _______ his son joined the army last year.

A. why　　 B. because　 C. as　　 D. that

　　　　 he has limited technical knowledge，the old worker has a lot of experience.?

A.Since　　　 B.Unless?　 C.As　　　　 D.Although

The reason for helping the man is _______ his son joined the army last year.

A. why　　 B. because　 C. as　　 D. that