3.29.

A. 　land

B. 　 sea

C. 　 soil

D. 　 flood

A. 　不填;the

B. 　不填;an

C. 　the; an

D. 　 a; the

A. 　 enters

B. 　 has entered

C. 　 was entering

D. 　 entered

A. 　 To have changed

B. 　 Change

C. 　 Changing

D. 　 Being changed

A. 　 give up

B. 　 giving up

C. 　 to give up

D. 　 having given up

A. 　 will be built

B. 　 will build

C. 　 was built

D. 　 built

A. 　 to

B. 　 at

C. 　 for

D. 　 with