题干

取一粒玉米种子,在其剖面滴一滴稀碘液,被染成蓝色的部分是 (   )

A:胚乳

B:胚轴

C:子叶

D:胚

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答案(点此获取答案解析)

A

同类题2

阅读下面的古诗文,完成下列各题。

【甲】

      鱼,我所欲也;熊掌,亦我所欲也。二者不可得兼,舍鱼而取熊掌者也。生,亦我所欲也;义,亦我所欲也。二者不可得兼,舍生而取义者也。生亦我所欲,所欲有甚于生者,故不为苟得也;死亦我所恶,恶有甚于死者,故患有所不辟也。如使人之所欲莫甚于生,则凡可以得生者何不用也?使人之所恶莫甚于死者,则凡可以辟患者何不为也?由是则生而有不用也,由是则可以辟患而有不为也。是故所欲有甚于生者,所恶有甚于死者。非独贤者有是心也,人皆有之,贤者能勿丧耳。

(节选自《鱼我所欲也》)

【乙】

      世有伯乐,然后有千里马。千里马常有,而伯乐不常有。故虽有名马,祇辱于奴隶人之手,骈死于槽枥之间,不以千里称也。

    马之千里者,一食或尽粟一石。食马者不知其能千里而食也。是马也,虽有千里之能,食不饱,力不足,才美不外见,且欲与常马等不可得,安求其能千里也?

      策之不以其道,食之不能尽其材,鸣之而不能通其意,执策而临之,曰:“天下无马!”呜呼!其真无马邪?其真不知马也。

(选自韩愈《马说》)

【丙】

      国破山河在,城春草木深。感时花溅泪,恨别鸟惊心。烽火连三月,家书抵万金。白头搔更短,欲不胜簪。

(选自杜甫《春望》)

同类题5

根据短文理解,选择正确答案。

    “Our aim is to take our art to the world and make people understand what it is to move,” said David Belle, the founder of parkour(跑酷).

    Do you love running? It is a good exercise, yet many people find it boring. But what if making your morning jog a creative one? Like jumping from walls and over gaps, and ground rolls? Just like the James Bond in the movie Casino Royale? Bond jumps down from a roof to a windowsill and then runs several blocks over obstacles on the way. It is just because of Bond's wonderful performances that the sport has become popular worldwide.

    Yes, that's parkour, an extreme street sport aimed at moving from one point to another as quickly as possible, getting over all the obstacles in the path using only the abilities of the human body. Parkour is considered an extreme sport. As its participants(参与者) dash around a city, they may jump over fences, run up walls and even move from roof top to roof top.

    Parkour can be just as exciting and charming as it sounds, but its participants see parkour much more than that.

    Overcoming all the obstacles on the course and in life is part of the philosophy(理念) behind parkour. This is the same as life. You must determine your destination, go straight, jump over all the barriers as if in parkour and never fall back from them in your life to reach the destination successfully. A parkour lover said, “I love parkour because its philosophy has become my life, my way to do everything.”

    Another philosophy we've learnt from parkour is freedom. It can be done by anyone, at any time, anywhere in the world. It is a kind of expression of trust in yourself. It is only a state of mind. It is when you trust yourself that you earn energy.