题目: 设f(x)=2x-3x=2,则当x→0时()。A.f(x)与x是等价无穷小B.f(x)与x同阶但非等价无穷小C.f(x)是比x高阶的无穷小D.f(x)是比x低阶无穷小 答案: 参考答案:B解析:由,故f(x)与x同阶但非等价无穷小。
题型:选择题 读“中国沿32°N纬线地形剖面图”,完成第小题小题1:有关我国地形、地势的叙述,正确的是( ) A.地形复杂多样,平原面积广大B.地势中高周低,呈阶梯状分布C.地形山谷相间,纵列分布D.山区面积广大,山脉构成地形的基本骨架小题2:有关图中代码表示的地形区,叙述正确的是( ) A.②为柴达木盆地,属第一级阶梯B.①为云贵高原,属第二级阶梯C.③为长江中下游平原,属第三级阶梯D.④为太行山,是第二、三级阶梯的分界线 查看答案
题型:单项选择题 Woman: I can't wait to see the look on Ted's face when he opens up our gift. Man: Neither can I. Question: What does the man meanA.He already knows what Ted will say.B.He doesn't have time to look at the gift.C.He can't imagine what his friends got for him.D.He's anxious to see Ted's reaction to the gift. 查看答案
题型:单项选择题 法洛四联症中的畸形包括()A.肺动脉狭窄、房间隔缺损、主动脉骑跨、左心室肥厚B.肺动脉狭窄、房间隔缺损、室间隔缺损、右心室肥厚C.肺动脉狭窄、房间隔缺损、主动脉骑跨、右心室肥厚D.肺动脉狭窄、室间隔缺损、主动脉骑跨、左心室肥厚E.肺动脉狭窄、室间隔缺损、主动脉骑跨、右心室肥厚 查看答案