喉癌可分成声门上型、声门型、声门下型和跨声门型、其中声门下型约占喉癌病例的（）
A.5%
B.10%
C.15%
D.20%
E.25%
参考答案：A
心理学是研究人的心理现象及其规律的科学。
The islands developed on their own for 80 million years and ________ have many rare animals found nowhere else.
A．soon
B．so
C．early
D．yet
