单项选择题
A．why you need extra time when you visit Arab countries B．how to be polite when doing business in the Arab world C．why Arab officials are so busy D．why personal relationships are important when doing business in the Arab world
A．security alarm systems can only be installed in commercial and industrial establishments and in large homes B．security alarm systems are still very expensive C．now, people can buy low-cost security alarm systems and install themselves D．security alarm systems can't scare off vandals
A．to cut the loaf; sharpen B．cutting the loaf; sharpen C．to cut the loaf with; sharpening D．cutting the loaf with; sharpening