重力式挡土墙衡重式墙背因采用陡直的墙面，且下墙采用( )墙背，因而可以减小墙身高度

下列指标中，（）不是CD-ROM驱动器的主要技术指标。

A.平均出错时间

B.分辨率

C.兼容性

D.感应度

流感病毒是一种RNA病毒，其表面含有血凝素和神经氨酸酶等蛋白质。血凝素能与细胞膜特异性结合，帮助病毒侵入宿主细胞内。神经氨酸酶能够让新产生的病毒从细胞中释放出来。请回答问题：

病毒侵入人体细胞后，机体产生的（）细胞能够与该病毒的宿主细胞结合，并裂解宿主细胞。

A punctual person is in the habit of doing a thing at the proper time and is never late in keeping an appointment.
The unpunctual man, on one hand, never does what he has to do at the proper time. He is always in a hurry and in the end loses both time and his good name. A lost thing may be found again, but lost time can never be regained. Time is more valuable than material things. In fact, time is life itself. The unpunctual man is for ever wasting and mismanaging his most valuable asset as well as other’s. The unpunctual person is always complaining that he finds no time to answer letters, or return calls or keep appointments promptly. But the man who really has a great deal to do is very careful of his time and seldom complains of want of it. He knows that he can not get through his huge amount of work unless he faithfully keeps every piece of work when it has to be attended to.
Failure to be punctual in keeping one’s appointments is the sign of disrespect towards others. If a person is invited to dinner and arrives later than the appointed time, he keeps all the other guests waiting for him. Usually this will be regarded as a great disrespect to the host and all other guests present.
Unpunctuality, moreover, is very harmful when it comes to do one’s duty, whether public or private. Imagine how it would be if those who are put in charge of important tasks failed to be at their proper place at the appointed time. A man who is known to be habitually unpunctual is never trusted by his friends or fellow men.

Which of the following statements best describes the harm of unpunctuality

A. If you are an unpunctual person, you cannot be in charge of any important task.
B. If your friends know that you are unpunctual, they may not see you again.
C. Unpunctuality may bring about heavy losses for both public and private affairs.
D. Unpunctuality may make you miss a lot of appointments and lose friends.

甲公司与乙公司协议合作开发某产品的生产新技术，共享利益。但当乙公司主张申请专利时，甲认为技术还不成熟，一旦公开将丧失其秘密性，故不同意申请。乙公司见此状况遂独自申报专利，但被专利局驳回。后乙公司与甲公司几经协商，甲公司声明放弃其共有的专利申请权。乙公司再次向专利局申报专利，获得了批准。
乙公司与丙公司签订专利实施许可合同，约定将该专利由丙公司独家实施，丙公司支付使用费。3个月后，丙公司拒绝向乙公司支付使用费，理由是甲公司也在使用该专利技术。后经调查，丙公司将该专利技术秘密许可丁公司使用。
根据上述事实，分析下列问题：

丙公司能否将该专利技术再授予丁公司使用

农业种子