问题

In communication, a smile is usually________ strongsign of a friendly and ________ open attitude.
A:Stay Focused on Your Work
B:Take Breaks WhenNecessary
C:If you have an officedoor, close it
D:the an
B:Take Breaks WhenNecessary
C:If you have an officedoor, close it
D:the an
正确答案是: