21.  Tensions within the factory workers are dying down, becoming a good sign for the owners. ............... as the manager has announced to leave the factory to form a new one.
 
      1.However, a new issue is boiling up   
      2.In fact, this situation is becoming worse   
      3.The opposite sign is that anything has gone wrong  
      4.On the contrary, this situation seems to be less serious  

22.  The Great Wall of China is reputed as one of the seven construction wonders in the world, ............ for its long history ............. for its massive construction size, along with its unique architectural style.
 
      1.either...or  
      2.not only...but also   
      3.rather...than  
      4.neither...nor