皮皮学，免费搜题
登录
搜题
【简答题】
已知四棱锥S-ABCD，底面为正方形，SA⊥底面ABCD，AB=AS=a，M、N分别为AB、SC中点． （Ⅰ）求四棱锥S-ABCD的表面积； （Ⅱ）求证：MN ∥ 平面SAD．
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】—It's raining! When did it start? —I don't know exactly. In fact, it ______ all this afternoon. [ ]
A.
lasts
B.
has lasted
C.
lasted
D.
will last
【简答题】It’s to water the flowers
when it is raining.
【单选题】— It’s raining! When did it start? — I don’t know exactly. In fact, it _________ all this afternoon.
A.
lasts
B.
lasted
C.
has lasted
D.
will last
【单选题】When a pet dog eliminates in the house while it's raining hard, it ______.
A.
indeed takes a revenge on its owner
B.
is showing fear to the bad weather
C.
doesn't take a revenge on its owner
D.
wants the house to be as wet as the outside
【单选题】失去控制的船舶夜间在航时除显示两盏垂直环照红灯外( )。
A.
不应再显示其他号灯
B.
应显示舷灯和尾灯
C.
对水移动时，还应显示舷灯和尾灯
D.
对水移动时，还应显示桅灯、舷灯和尾灯
相关题目：