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    Don't be surprised if you see a car going down the road without a driver in Beijing these days.In march, 2018, baidu was given a license to test its self-driving cars in Beijing, China Daily reported.

    Self-driving cars have been in development since 2010, when google announced that it was making such cars. Since then, companies like Tesla, Uber and Baidu have been working to produce and test their own self-driving cars.

    Self-driving cars are expected to change the way we get around. They are safer and more environmentally friendly than regular cars. They can remove the stress(压力) of driving and allow disabled or blind people to get around more easily.

    But self-driving cars have their own disadvantages as well. In one test, researchers pointed a laser pointer(激光棒) at the car's sensors(感应器) while it was moving. The car mistakenly thought that the laser beam(波束) was in its way and slowed down or changed directions.

    The software(软件) that is used to direct the cars may not be safe enough. Reported Live science. Sometimes, without any reasons,it may break down when we use our computers or smartphones. If the software in a self-driving car happened to crash. The results could be deadly.Maybe improvements to the software could solve this problem.

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同类题3

自交不亲和性是指某一植物的雌雄两性机能正常,但不能进行自花传粉或同一品系内异花传粉的现象.如某品种烟草为二倍体雌雄同株植物,却无法自交产生后代.请回答问题:

(1)烟草的自交不亲和性是由位于一对同源染色体上的复等位基因(S1、S2…S15)控制,以上复等位基因的出现是____ 的结果,同时也体现了该变异具有____ 特点.

(2)烟草的花粉只有通过花粉管伸长(花粉管由花粉萌发产生)输送到卵细胞所在处,才能完成受精.下表为不亲和基因的作用机制:

亲本组合

S3S4♂×S1S2♀

S1S2自交

S1S2♂×S1S3♀

花粉管萌发情况

基因型为S3和S4的花粉,其花粉管都能伸长

基因型为S1和S2的花粉,其花粉管均不能伸长

只有基因型为S2花粉,其花粉管能伸长

将基因型为S1S4的花粉授于基因型为S2S4的烟草,则子代的基因型为____ ;若将上述亲本进行反交,子代的基因型为____ .自然条件下,烟草不存在S系列基因的纯合个体,分析原因是____ .

(3)科学家将某抗病基因M成功导入基因型为S2S4的烟草体细胞,经植物组织培养后获得成熟的抗病植株.如图,已知M基因成功导入到S2所在II号染色体上,但不清楚具体位置.现以该植株为____ (父本或母本),与基因型为S1S2的个体杂交,根据子代中的抗病个体的比例确定M基因的具体位置.

Ⅰ.若后代中抗病个体占____ ,则说明M基因插入到S2基因中使该基因失活.

Ⅱ.若后代中抗病个体占____ ,则说明M基因插入到S2基因之外的其它部位.