心脏瓣膜病中________＿最常受累，其次为__________
参考答案：二尖瓣；主动脉瓣
_____ to his experiment in the lab, the idea for the new plan came to his mind. [ ]
A. While devoting
B. While devoting himself
C. While he was devoted
D. While devoted
叶片的共振频率
