阅读诗歌,回答问题
望洞庭湖赠张丞相
孟浩然
八月湖水平,涵虚混太清。气蒸云梦泽,波撼岳阳城。
欲济无舟楫,端居耻圣明。坐观垂钓者,徒有羡鱼情。
Bill doesn't like the sunglasses in the ad because they can't __________ the sun well.
在山岳地区,公路常建造成“之”字形,原因是( )