汇票的“出票”，就是出票人在汇票上写明有关内容并签名的行为。（）
参考答案：错
Fred, who had expected how it would go with his daughter, had a great worry ______ his mind.
A．in
B．on
C．with
D．at
简述四冲程柴油机混合气的形成。
