雪花：冬天
A．梧桐：行人
B．落叶：秋天
C．微风：夜晚
D．欢快：小溪
参考答案：B
解析： 事物出现的特殊时节。雪花到冬天才会有，落叶到秋天才会有。
His first book ______ next month is based on a true story of his family.
A．published
B．to be published
C．to publish
D．being published
Gq口为AF和PDF的接口，对于每一个AF会话，该AF只能与单个PDF进行交互。
