【判断题】若“学生信息”表与“学生档案”表结构一样,将“学生信息”表中的所有内容添加到“学生档案”表中,则相应的SQL语句是INSERT INTO学生信息 SELECT* FROM学生档案。
【单选题】电梯能关门,但不能自动开门,最有可能的原因是( )。
C.
门安全触板或门光电开关(光幕)动作不正确或损坏
【单选题】关于砌筑砂浆强度的说法,错误的是( )。
A.
砂浆的强度是将所取试件经28d标准养护后,测得的抗剪强度值来评定
C.
每250立方米砌体、每种类型及强度等级的砂浆、每台搅拌机应至少抽检一次
【多选题】下列有关内部收益率的说法,正确的是( )。
E.
在内部收益率的计算过程中,如果计算出NV为正值,则应该试算一个较高的折现率
【单选题】电梯能开门,但不能自动关门,最有可能的原因是( )。
C.
门安全触板或门光电开关(光幕)动作不正确或损坏
【单选题】Which is true of the following statement about the nuclear envelope
A.
All cells have nuclear membranes;
B.
The nuclear membrane is composed of a unit membrane with a large number of ribosomes on the outside;
C.
There are nuclear pore complexes on the nuclear membrane, and all material transport needs to go through the nuclear pore complex;
D.
The nuclear membrane is a selective permeable membrane
【多选题】How is the nuclear envelope supported by a meshwork of intermediate filaments?
A.
Whereas cytoplasmic intermediate filaments form ropelike structures, the intermediate filaments lining and strengthening the inside surface of the inner nuclear membrane are organized as a two-dimensional meshwork.
B.
The intermediate filaments that form this tough nuclear lamina are constructed from a class of intermediate filament proteins called lamins (not to be confused with laminin, which is an extracellular matrix protein). The nuclear lamina disassembles and reforms at each cell division, when the nuclear envelope breaks down during mitosis and then re-forms in each daughter cell.
C.
The collapse and reassembly of the nuclear lamina is controlled by the phosphorylation and dephosphorylation of the lamins.
D.
Phosphorylation of lamins by protein kinases weakens the interactions between the lamin tetramers and causes the filaments to fall apart. Dephosphorylation by protein phosphatases at the end of mitosis allows the lamins to reassemble.
【单选题】下列关于虚方法的描述中,正确的是( a )。
A.
虚方法能在程序执行时动态确定要调用的方法,因此比非虚方法更灵活
B.
在定义虚方法时,基类和派生类的方法定义语句中都要带上virtual修饰符
C.
在重写基类的虚方法时,为消除隐藏基类成员的警告,需要带上new修饰符
D.
在重写基类的虚方法时,需要同时带上virtual和override修饰符