1 . The children played in the courtyards and because of the hutongs, courtyards ________ together for miles around ________ a network of people working, playing and living together-a real community.

A．was joined… creating	B．were joined… to create
C．joined… to create	D．joining… created

2 . We also lose heat by transporting the blood to the surface of the skin ________ it can lose heat out into the external environment.

A．when

B．so

C．where

D．unless

3 . He ________ for the unexpected accident causing considerable losses so he cannot but ________ his mistake due to carelessness.

A．was blamed… admit	B．was to blame… admit
C．had been blamed… to admit	D．was to blame… to admit

4 . In a world ________ by cooperation rather than isolation, the pattern of sharing tasks and decisions ________ for equality.

A．characterized… makes	B．characterized… are made
C．characterizing… are made	D．characterized… is made

10 . Given that cleaning up the environment is a collective effort, we will not be able to achieve significant progress ______ everyone takes responsibility for their action.

A．while

B．since

C．until

D．unless