The bird watchers were on the ______ for the rare species.A．alterB．alertC．alikeD．altar

On the____wome make only two birds of what men earn.A．contraryB．standardC．averageD．level

During the Games, on the evening before the moon was full ______.A．sheep and cattle were s

The original inhabitants on the North American Continent were the______.A．EskimosB．Aborigi

At the very beginning, the blues were______.A．not performed on formal occasionsB．tradition

The students were so fascinated by the______Yangtze River that they spent hours sitting on

We drove to the dump and were back on the _____ by 1 ：00.A.avenueB.trackC.routeD.barr