中央电视台《每周质量报告》在4月15日播出的节目中曝光了13种铬超标胶囊药物，这些“毒胶囊”其成分含有不可食用的工业明胶，铬含量严重超标．铬是一种毒性很大的重金属，下列含铬的物质中Cr（铬）元素的化合价最高的是（　　）

A．Cr

B．K₂Cr₂O₇

C．Cr₂（SO₄）₃

D．CrCl₂

Computers will become more advanced and they will also become easier to use.Improved speed recognition will make the operation of a computer easier.Virtual reality(虚拟现实),the technology of (71) with a computer using all of the human senses,will also contribute to better human and computer (72). Other, exotic(奇异的) models of computation are being developed,including biological conputing that uses living organisms,molecular computing that uses molecules with particular (73),and computing that uses DNA,the basic unit of heredity(遗传),to store data and carry out operations.These are examples of possible future computational platforms that,so far,are limited in abilities or are strictly (74). Scientists investigate them because of the physical limitations of miniaturizing circuits embedded in silicon. There are also (75) related to heat generated by even the tiniest of transistors.

（72）处填（）。

A．interfaces

B．behavior

C．similarities

D．comparison