单项选择题
A．spend some time being polite and offering refreshments first B．ask you to wait for several minutes first C．introduce you to some strangers first D．start talking business immediately
A．good locks are essential to home's security B．there are many types of security alarm systems for the home C．an ounce of prevention is worth a pound of cure D．there are burglar alarm systems that can be installed without professional help
A．change the topic B．get too close to you C．make a decision. D．limit his choice