The American economy is still in trouble,________ the Chinese economy is beginning to pick up.
The field research will take Joan and Paul about five months; it will be a long time _____ we meet them again.
All the travelers _____that they should bring their ID cards with them.
There is a big dog _______to a fence outside the house.
The fog was so heavy this morning that drivers could hardly ________ the things just ten meters away from them.
This is the most serious and worst situation ___ I have ever experienced as a fan of the NBA. A. which B. that C. whenD. where