下列关于DNA双螺旋结构的叙述，哪一项是正确的

A．磷酸核糖在双螺旋外侧，碱基位于内侧

B．碱基平面与螺旋轴平行

C．遵循碱基配对原则，A与G配对，T与C配对

D．两条多聚核苷酸链的走向呈正向平行

You want to use the Web to let Eternal users or your customers look at corporate information. But you want to keep installation at the user end (66) and you don’t want just anyone to get (67) your databases.

That may be where an application server enters the picture. For more user machine independent, these t software packages, typically written in the (68) programming language.

for use on Windows NT-based systems, act as go-betweens linking browser-equipped end users to the databases that (69) the information they need to (70) 。

（66）处填（）。

A．simple

B．simply

C．single

D．singly