The traveler _____ his map to make sure he was not lost．（ ）
A．looked afterB．looked up
C．looked forD．looked down
﹣Sorry， I took the wrong seat．
﹣____． I will take yours instead．（ ）
A．No wayB．Better not
C．Excuse meD．That's all right
Our business won't improve ____ we offer better service to our customers．（ ）
A．becauseB．unlessC．afterD．since
I came to school ____ this morning because it was my turn to clean our classroom．（ ）
A．earlyB．slowlyC．quietlyD．suddenly
The villagers expect that the building of the bridge ____ before the rainy season comes．（ ）
A．is completedB．was completed
C．will be completedD．has been completed
﹣Shall we go to the airport to ___ your sister？
﹣I don't think it's necessary． She will come here by taxi．（ ）
A．see offB．pick up
C．look afterD．come across