单选题 ______ the fire alarm, all employees evacuated the building quickly and orderly.

单选题 The natural beauty of the mountains served as the ______ for many of her famous poems.

单选题 Unexpected advertisements often ______ on my computer screen when I browse the internet.

单选题 This semester has shown me that there are ______ limitless options to explore before declaring my major next year.

单选题 I need to ______ my passport before traveling to Europe next month because it will not be valid soon.

单选题 After participating in the earthquake search and secure, he is ______ becoming a firefighter.

单选题 In the heart of Harvard Square, you can find the Starbucks ______ by many students truly.

单选题 The success of this project depends on close ______ between all team members from different departments.

单选题 As soon as I ______ Harvard, everything felt right. The campus, the people, all made me realize there was no place else I wanted to spend the next four years.