本文關(guān)鍵詞：學(xué)會生存作文400字，由筆耕文化傳播整理發(fā)布。

學(xué)會生存作文400字

生存作文是在叢林的話可以抓  注意 千萬不要用手抓用些的東西 要堅硬用手之前要確定它死了 在生火烤千萬不要身上有傷口有的話最好不要吃 怎樣識別有毒蛇和無毒蛇呢，一般人單憑頭部是否呈三角形或者尾巴是否粗短，或者顏色是否鮮艷來區(qū)分，這是不夠全面的。雖然毒蛇頭部呈明顯的三角形，但也有的毒蛇，，頭部并不呈三角形；而無毒蛇中的偽蝮蛇，頭部倒是呈三角形的。五步蛇、腹蛇和眼鏡蛇的尾巴確實(shí)很粗大，但烙鐵頭的尾巴就較細(xì)長；很多色澤鮮艷的蛇，如玉斑錦蛇、火赤鏈蛇等并非是毒蛇，而蝮蛇的色澤如泥土或似狗屎樣，很不引人著目，但卻很毒。因此區(qū)別有毒和無毒蛇主要根據(jù)以下幾點(diǎn)：
Survival composition is in the jungle it can catch do not pay attention to grab some stuff to hard hand prior to determine it died in the fire roasted never had a wound so it is best not to eat how to identify the serpent and non-poisonous snakes, generally a head is triangular or tail is coarse short, or whether the bright colors to distinguish, it is not comprehensive enough. Although the snake head were triangular, but also some snakes, the head is triangular; without the viper in the pseudo viper, the head is triangular. Agkistrodon acutus, vipers and cobra 's tail is very thick, but iron head tail is slender; many bright color snake, Elaphe Mandarina, such as fire Dinodon rufozonatum not venomous snakes, and viper color such as soil or the like shit, very obscure the eyes, but poisonous. So the difference between toxic and harmless mainly according to the following points:
1、毒腺 有毒蛇具有毒腺，無毒蛇不具有毒腺。毒腺是由唾液腺演化而來。位于頭部兩側(cè)、眼的后方，包藏于頜肌肉中，能分泌出毒液。當(dāng)毒蛇咬物時，包繞著毒腺的肌肉收縮，毒液即經(jīng)毒液管和毒牙的管或溝，注入被咬對象的身體內(nèi)使之發(fā)生中毒，無毒蛇無這一功能。
1, poisonous snake venom gland with venom, snake venom toxicity does not have. Venom is produced by the salivary glands evolved. Located on both sides of the head, eyes in the jaw muscles in the rear, parcel, can secrete venom. When the snake bite, surrounds the venom gland muscle contraction, venom by venom duct and fangs pipe or ditch, was injected into the bite object within the body to produce toxic, non-poisonous snakes without this function.
2、毒液管 是輸送毒液的管道，連接在毒腺與毒牙之間。只有毒蛇才具備有毒液管。
In 2, venom duct is connected in the pipeline conveying venom venomous fangs, and between. Only the Viper to have venom duct.
3、毒牙 毒蛇具有毒牙，它位于上頜骨無毒牙的前方或后方，比無毒牙既長又大。
In 3, the Viper has fangs fangs, it is located in the maxilla without fangs in the front or rear, than the long and large fangs.

  本文關(guān)鍵詞：學(xué)會生存作文400字，由筆耕文化傳播整理發(fā)布。