Why were people encouraged to participate in the Big Butterfly Count?

• A、To understand anxiety.

• B、To connect with others.

• C、To find new butterfly species.

• D、To help with a science project.

He （ ） at the company for five years before he was promoted to a management position.

• A、had worked
• B、has worked
• C、was working
• D、will have worked

61．學生會打算舉辦一場舊書交換活動。請你給全校同學寫一份通知，內容包括：

·舊書交換的好處（如培養節約習慣、增強環保意識等）；

·舊書交換活動的時間及地點；

·可以交換的舊書類別（如課本、小說等）；

·號召大家積極參與。