A、  B、  C、  D、  Ca pair of意为“(眼镜或是袜子等)一副，一对”。sunglasses意为“太阳镜”。(A)left是leave的过去分词，leave one’s seat意为“离开座位”。(

(A)The signs are being painted.
(B)The building is under construction.
(C)The bicyclists are riding through the streets.
(D)Some cars are parked on the street.

(A) The woman has left her seat.
(B)The men are leaning across the table.
(C)There is a pair of sunglasses on the table.
(D)The woman is putting some flowers in a vase.