A:since
B:when
C:that
D:before
如果直线2ax﹣by+14=0(a>0,b>0)和函数f(x)=mx+1+1(m>0,m≠1)的图象恒过同一个定点,且该定点始终落在圆(x﹣a+1)2+(y+b﹣2)2=25的内部或圆上,那么ba的取值范围____
Some students are playing soccer, and the __________ are swimming.
mRNA上决定氨基酸的某个密码子的一个碱基发生替换,则识别该密码子的tRNA及转运的氨基酸发生的变化是
Such things are not common for me, _________ they are usual.