I单项选择。（每题1分，共30分)
( )1. Once upon a time, there was _________emperor in _________Europe.
A. a, a B. an, an C. a, / D. an, /
( )2. I will send you a message as soon as I .
A. get B. gets C. got D. getting
( )3. I won’t finish until ten o’clock.
A. work B. works C. to work D. working
( )4. We’ll visit Shanghai this Sunday it rains.
A. since B. if C. unless D. until
