电视纪录片《第三极》聚焦青藏高原,与南北两极比,它是唯一有人类生存活动的“极地”地带。读图,回答小题 3.青藏高原被誉为世界“第三极”的原因是( ) A.高寒 B.湿热 C.干燥 D.炎热 4.青藏高原地形的显著特征是( ) A.山河相间,纵列分布 B.山环水绕,沃野千里 C.千沟万壑,--Where is Betty? I haven't seen her for days.--She________ Yellowstone Park with her family.A.has been toB.has gone toC.went toD.will go to