问题
选择题
圆x2+y2=4被直线
|
答案
圆半径是2，圆心到直线距离是
=|
×0+0-23
|3 3+1
，圆被直线截得的劣弧所对的圆心角的大小为3
；π 3
故选C．
搜题请搜索小程序“爱下问搜题”
圆x2+y2=4被直线
|
圆半径是2，圆心到直线距离是
=|
×0+0-23
|3 3+1
，圆被直线截得的劣弧所对的圆心角的大小为3
；π 3
故选C．
词语填空。用方框中所给单词的适当形式填空，使短文通顺、正确、连贯(每个单词限用一次)。
There are about nine million rock climbers in the United States. Some do it just for fun. 小题2:compete (竞赛). Rock climbing can be 小题3:, but there are many ways 小题4:can protect climbers. They hope to challenge 小题5:through climbing. There are several kinds of rock climbing. Traditional 小题6:is done outside. Climbers use ropes and equipment to climb many 小题7:of meters up. Sport climbing is similar. There is 小题8:indoor climbing. Rock walls made of wood or concrete(混凝土) have places for climbers’ hands and 小题9:. Nowadays, many American teenagers take part 小题10:the activity of rock climbing. It is a great way to build their confidence and strength. |
