如图,已知直四棱柱中,,底面是直角梯形,是直角,,求异面直线与所成角的大小.
_______ from his _______ look, I know he would accept the decision without any consideration. A. Judge, pleased B. Judged, pleasure C. Judging, pleasant
一种蛾中控制浅颜色的等位基因是隐性的,控制深颜色的等位基因是显性的。假设有640只浅色的蛾和360只深色的蛾,群体是哈迪——温伯格平衡,那么
下列物理量属于标量的是( )A.速度 B.位移 C.功 D.电场强度
The two brothers look so much alike that it is difficult to ______. A. tell them from B. tell from them C. tell apart them D. tell them apart
“稻花香里说丰年,听取蛙声一片”。雄蛙在稻田里高声鸣叫以吸引雌蛙,这种行为属于A.社群行为 B.生殖行为 C.觅食行为
沙坡是河床底部的一种微地貌类型,一般河流中均有存在。它是流水搬运、沉积作用的一种结果。读下图,回答问题。 若该河流分布在南半球,则能正