The dictionary belong to Sam．You can see his name on it．（ ）
| A． |
can |
B． |
must |
C． |
need |
D． |
would |
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
﹣I wonder ____ the students have a physical examination．
﹣Once a year．（ ）
A．how farB．how soonC．how longD．how often