As the sea ice melts sooner each swimmer,polar bears are forced to come ashore earlier and face food shortages _____ they have stored enough fat to last them through the season.
| A．before | B．unless | C．since | D．until |
. I failed in the final examination last term and only then____ the importance of studies.
A I realized B I had realized C had I realizedD did I realize
. On the opposite wall____ one map____ dozens of pictures.
A hang, including B are hung, together with C is hanged, with D is hanging, as well as
. So absorbed _____ in her work that she didn’t realize I was behind her.
A had sheB was sheC she had D she was
By the side of the Bird’s Nest_____, completed in 2008.
A there standing the Water Cube B does the Water Cube stand
C the Water Cube standsD stands the Water Cube
. _______, he always tries his best to complete it one time.
A However the task is hardB However hard the task is
C Though hard the task is D Though hard is the task