本题的关键点为“电子商务”、“支柱”。由图可知,电子商务的各类应用是建立在政策法律和技术标准两大支柱上的。因此本题选“A”。
Complete the following sentence with a (compound) word derived from the one(s) given in bracket.
There are no ( ) allies and enemies among countries. National interest is constantly uniting or dividing nations.(ever, last)