When you hear Westerners（西方人）say “ Drop in anytime”（随时来玩）or “Come and see me soon” , you should realize that it doesn’t mean you are welcome to come over to their house anytime. It’s wise to telephone before visiting someone.
Never accept an invitation unless you really plan to go. You may refuse by saying, “Thank you for inviting me, but I may not be able to come.” If you are unable to come after accepting the invitation, be sure to tell those who invite you in advance（提前）that you will not be there.
When you have accepted the invitation to a party or a dinner, it is polite to bring small gifts with you, such as bottles of drink, flowers and chocolate. Sometimes Westerners may take you out to dinner in a restaurant and it does not necessarily mean that he is going to pay the bill at the end of the meal. He might want you to “go Dutch”, which means each person pays his own bill.
小题1:The best title of this passage is ________
A．Drop in anytime.
B．Come and see me soon.
C．Invitation in western countries.
D．Westerners.小题2:When Westerners say “ Drop in anytime” or “Come and see me soon” , it means ________
A．you are welcome to visit them anytime
B．you are welcome to visit them, but you still need to call them before going to their house.
C．they don’t want you to visit them.
D．they will hold a party for you.小题3:If a westerner invites you to go to his house, ________
A．you may refuse if you don’t plan to go.
B．you have to accept the invitation even you don’t want to go.
C．you can’t accept the invitation.
D．and you accept the invitation, you must go.小题4: If you have accepted the invitation to a party or a dinner, what kind of gifts will you bring? ________
A．Money.
B．Televisions
C．Computers.
D．Books小题5:The underlined part “go Dutch” means “________” in Chinese.
A．去荷兰
B．去Dutch这家餐厅
C．实行 AA制
D．请客
是A的伴随矩阵，则下列等式或命题中，正确的是（）。