皮皮学,免费搜题
登录
搜题
【单选题】
生物碱碱性最强的是
A.
季铵生物碱
B.
酰胺生物碱
C.
胺生物碱
D.
伯胺生物碱
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】如图 所示 , 质量为 m 的物体用平行于斜面的细线联结置于光滑的斜面上,若斜面向左方作加速运动,当物体刚脱离斜面时,它的加速度的大小为
A.
gsin
B.
gcos
C.
gtan
D.
gcot
【判断题】两个非零向量a,b的向量积满足交换律,即 .
A.
正确
B.
错误
【简答题】In those days even bicycles were very dear and hard to ______, and coupons were issued for them.
【简答题】And even graves themselves soon ______back into the soil.
【单选题】Some people say that if the holder of chopsticks pushes them______ his stomach to even them up instead of tapping them on the table, the chances are he is a coolie.
A.
on
B.
against
C.
at
D.
to
【判断题】两个向量的向量积满足交换律。
A.
正确
B.
错误
【单选题】Every minute is made full _____ of _____ our lessons well.
A.
to use; study
B.
use; studying
C.
use; to study
D.
used; studying
【单选题】Much to her delight, three _________ neighbors showed up and several of them even brought with them some candies and cookies.
A.
dozens
B.
dozen
C.
dozen of
D.
dozens of
【单选题】如图所示,质量为m的物体用平行于斜面的细线联结置于光滑的斜面上,若斜面向左方作加速运动,当物体刚脱离斜面时,它的加速度的大小为
A.
B.
C.
D.
D
【单选题】如图所示,质量为m的物体用平行于斜面的细线连接置于光滑的斜面上,若斜面向右方作加速运动,当物体刚脱离斜面时,它的加速度的大小为( )
A.
;
B.
;
C.
;
D.
相关题目: