21. These flowers love warm, humid _______ , so please water them frequently and place them in a warm room.
A. atmosphere B. condition
C. space D. room
【解析】选A。考查名词。句意：这些花喜爱温暖潮湿的空气。因此请经常给它们浇水并把它们放在温暖的房子里。atmosphere“空气，氛围”。condition“条件”是可数名词，space空间，room房间。因此只有A项符合句意。
22. If you look out of the window on the right of the train, you’ll see that we’re now _______ the mountain areas.
A. approaching B. arriving
C. conquering D. coming
【解析】选A。考查动词。arrive和come都是不及物动词，后面不直接跟表地点的名词。approach“走近”，句意：如果你透过右边的窗户往外看，你就会看到我们正走近山区。conquer“占领，攻克”，与句意不符。
