양궁인 듯 양궁 아닌 다트다트는 영국의 왕이었던 헨리 8세가 궁수를 훈련시키기 위해 고안했다고 해요. 궁수가 비 오는 날에 목표물을 정확하게 맞히는 연습을 하도록 실내에서 작은 화살촉을 나무판에 던지게 한 것이 다트의 시초이지요. 이후 장비가 간단하고 좁은 공간에서 즐길 수 있다는 장점 ...
medium for adult education. For example, in the Indian state of Gujarat, Chitrageet is a hugely popular show that plays Bollywood song and dance clips. The routines are subtitled in Gujarati. Within six months, viewers had made a small but significant improvement in their reading skills. Too much TV has been associated with violence, obesity and social isolation. But TV is having a positive ...
smaller than any of the forces involved in these everyday spinning things. The Coriolis force is so small, that it plays no role in determining the direction of rotation of a draining sink anymore than it does the direction of a spinning CD.The direction of rotation of a draining sink is determined by the way it was filled, or by vortices introduced while washing. The magnitude of these ...
they've discovered a "cell division cycle protein"(cdc2) which, with the help of another protein called "cyclin," plays a key role in mitosis. Changes occur in the linked proteins that line the membrane around the cell's nucleus, presumably so the cell can then divide. Since cdc2 protein occurs in all cells (human cdc2 protein is said to be 63 percent similar to that of the most primitive ...
동아사이언스
디라이브러리
DS스토어
팝콘플래닛
