【简答题】函数 的第二类间断点为 _______;(直接填阿拉伯数字)
【单选题】在 Oracle 中,下面那条语句当 Comm 字段为空时显示 0 ,不为空时显示 Comm 的值()
A.
select ename, NVL(comm,0) from emp;
B.
select ename, NULL(comm,0) from emp;
C.
select ename, NULLIF(comm,0) from emp;
D.
select ename, NVL2(comm,0) from emp;
【单选题】将某种生物基因组转录的全部mRNA通过反转录合成cDNA,与载体连接,转化宿主细胞,得到含全部表达基因的克隆群体( )。
【单选题】In inter-gender communication when responding to hearing of someone else’s problems, ________
A.
Men tend to respond to hearing of someone else’s problems by telling of their own problems.
B.
Women tend to show that they understand the situation the other person is in and that they feel sympathetic.
C.
Women are more likely to take it as a request for help.
D.
Women tend to offer a solution, however pointless the solution might be.
【单选题】函数 的间断点为 则此函数的间断点类型为( )
【单选题】若f(x)为奇函数,且f'(0)存在,则x=0是函数 的( )。
【单选题】函数【图片】的第二类间断点的个数为( )
【简答题】将某种生物基因组转录的全部mRNA通过反转录合成cDNA,与载体连接,转化宿主细胞,得到含全部表达基因的克隆群体 。