Answer:
A friendly smile and a firm handshake<em> were</em> working well for Eric
Explanation:
A friendly smile and a firm handshake was working well for Eric.
this is wrong
because A friendly smile is different and a firm handshake is also different
so we need to use<em> were</em> instead of <em>was</em>
<em></em>
<em>so a true sentence will be:</em>
A friendly smile and a firm handshake were working well for Eric.
