PEC（posta elettronica certificata）是认证电子邮件，是挂号信的有效替代品，在大约12年前就开始使用了。 意大利法律是强制公司、公共管理部门和专业职业人士使用PEC邮箱的。

2022年3月1日 · A tail throw occurs when a whale turns to its side and violently lifts its tail out of the water and slaps it down in a sideways action. Since it's believed tail throws primarily occur during mating, this action is very rare here in Hawaii. Pec Slap

PEC. The Pennsylvania Environmental Council is at the forefront of leading a four-state coalition working to complete and connect a 1,450-mile network of multi-use trails. PEC also prides itself in nurturing access to the state’s water trails for when you want to get off land. Learn more about PEC’s land and water trail work. Explore

2023年11月3日 · Attachments, innervation and functions of the pectoralis major muscle. The pectoralis major is a paired, superficial muscle located on the anterior surface of the thoracic cage. If you’re a gym lover, you’ll hear these muscles also being referred to as the pecs muscles.

2021年2月25日 · These remarkable encounters yesterday reminded us of why humpback whales are one of the most awesome whales to view. From pectoral fin slaps to tail slaps an...

Larger top part provides extra downward thrust, which with the large pectoral fins provide lift. Sharks must swim constantly to stay afloat and the tail-pec system boosts lift. Not very maneuverable. f) reverse -- lifts flying fish up out of water. The tail fin on a tuna is lunate, which is good for. speed.

2023年11月1日 · Humpback Whales will often pec slap to attract attention towards themselves which is a very important part of their communication. Female whales will often pec slap during the northern migration to call in the attention of nearby males and encourage the beginning of a competition pod.

2023年12月21日 · 本文将为您详细介绍公司运营过程中如何使用 PEC电子认证邮箱 。 什么是PEC电子认证邮箱？ PEC电子认证邮箱全称 Posta Elettronica Certificata ，官方定义为电子邮件交换系统，它允许企业收发具有法律效力的电子邮件，实际上可以理解为电子挂号信。

2002年1月1日 · Data from 5-years of behavioral observations of humpback whales on the Hawaiian wintering grounds were compiled and analyzed. Overall findings suggest pec-slapping behavior is dependent on the...

2021年8月6日 · Direct upload of some beautiful tail and pec-slapping by a #humpback #whale in Juneau, #alaska There's a surprise in there so many sure you watch the...