下列农业类型与地理区域组合正确的是( )
A:北方地区——水田为主的农业
B:南方地区——灌溉农业
C:青藏地区——高寒牧业和河谷农业
D:西北地区——旱地为主的农业
Football
People call it “the first sport in the world”. There are two teams in the football field during a game. Each team has eleven players.
Tennis
There is a big net in the middle of the court(球场). Each player has a racket(球拍)in his hand. Two or four players can play it together.
Golf(高尔夫球)
Golf comes from Scotland. It means green, oxygen, light and foot. People play it on the outdoor grass. They hit the white balls into the small holes with a stick.
Basketball
America is the hometown of basketball. This sport is famous for NBA.
There are two teams with ten players on the basketball court. They can't run with the ball in their hands.
如图,直角三角形金属框abc放置在匀强磁场中,磁感应强度大小为B,方向平行于ab边向上。当金属框绕ab边以角速度ω逆时针转动时,a、b、c三点的电势分别为Ua、Ub、Uc。已知bc边的长度为l。下列判断正确的是()
观察如图,阴影部分表示四种生物的共同特征,这一特征是( )