关于双联签名描述正确的是()
A、一个用户对同一消息做两次签名
B、两个用户分别对同一消息签名
C、对两个有联系的消息分别签名
D、对两个有联系的消息同时签名
参考答案:D
句型转换
1. I hope I'll be braver.(改为同义句)
I hope _ ___braver.
2. He is not a thoughtful boy .I think so.(合并成一个句子)
I he a thoughtful boy.
3. She is afraid to go out alone at night.(改为同义句)
She is afraid ____out alone at night.
4. That old woman talked too much ,and her voice was so loud.(改为同义句)
That old woman talked and ___ _____.
5.1t is easier to look after the short hair.(改为同义句)
It is easier to the short hair.
乙烯制冷压缩机出口出现超压现象,应果断打开火炬阀,一旦超压消除,应立即关闭放火炬阀,以防乙烯凝液收集罐空。