—Look! There are lots of old people in the park.

—They look relaxed. Some are playing the card , ___________ are chatting.

A．another

B．the other

C．other

D．others

经吸血节肢动物传播的传染病的流行特征是（）

A.无地区性，但有季节性

B.有地区性，但无季节性

C.有明显的职业特点

D.无明显的职业特点

E.发病年龄无差异