self-produced, spontaneous - taking place or arising without the need of apparent external trigger; "spontaneous laughter"; "spontaneous combustion"; "a spontaneous abortion"

即便有一些重大考试，也只是体现特定区域内的水平。比如中考体现的是全市水平，高考体现的是全省水平（上海、北京的英语高考卷就比全国卷要难度大）。

The chief attributes which recognize it as being a canid consist of the loss of the upper 3rd molar (Section of a pattern towards a far more shearing bite), as well as construction of the middle ear that has an enlarged bulla (the hollow bony structure guarding the delicate areas of the ear). Prohesperocyon possibly experienced marginally extended limbs than its predecessors, and likewise experienced parallel and carefully touching toes which vary markedly with the splayed arrangements with the digits in bears.[9]

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Encyclopaedia Britannica's editors oversee subject matter places through which they may have in depth awareness, whether from many years of working experience attained by working on that content or by way of examine for a sophisticated degree. They write new content and confirm and edit information received from contributors.

Individuals have been breeding dogs due to the fact prehistoric periods. The earliest dog breeders made use of wolves to build domestic dogs. From the start, human beings purposefully bred dogs to carry out many duties.

[36] Searching in packs has the edge that larger sized prey things is usually tackled. Some species type packs or are in smaller relatives groups with regards to the situation, such as the variety of obtainable meals. In the majority of species, some people today Are living by themselves. Inside of a canid pack, there is a technique of dominance so the strongest, most expert animals guide the pack. Usually, the dominant male and woman are the only real pack customers to breed.[37]

Canines bear as number of as 4 and as many as 20 offspring following a gestation period of about fifty to eighty days. The youthful nurse for 4 to six months. Smaller canines species achieve sexual maturity at all over a yr, but larger species similar to the wolf just take no less than two years to achieve reproductive age.

All natural childbirth natural gas natural source natural collection natural dye natural law non-natural See all meanings Idioms and phrases somebody's natural mom/father/dad or mum phrase

tunes of or referring to a trumpet, horn, etc, without having valves or keys, on which webpage only notes of your harmonic number of the keynote is often acquired

A well-exercised Pet is commonly a well-behaved Doggy, and obtaining Imaginative ways to obstacle them contributes to a satisfying daily life for each pet and owner.

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Individuals who choose medicines that raise urine output may be additional more likely to have night leg cramps. But it's actually not regarded if there's a immediate backlink.

They’re able to react to stimuli in a very calculated way, normally devoid of growling, lunging, or displaying indications of stress. These 10 tranquil Puppy breeds thrive in environments with young children, More Help in clinical environments as therapy dogs, or simply dealing with other animals as herders or guardians.