某种商品进价为a元/件，在销售旺季，商品售价较进价高30%；销售旺季过后，商品又以7折（即原售价的70%）的价格开展促销活动，这时一件该商品的售价为（　　）

(二)

    This is my room. Near the window there is a desk. I often do my homework at the desk. You can see some books, some flowers, a ruler and a pen on it. On the wall near the desk there is a picture of a cat. There is a clock above my bed. I usually put my football under my bed. There is a chair in front of the desk. I can see the trees and the roads outside when I sit there.

 阅读短文，选择最佳答案。

You often clean the kitchen by _______.