一物块沿斜面匀速下滑，如图关于该物块受力的示意图正确的是（　　）

增加：在缺词处加一个漏字符号（∧）,并在其下面写出该加的词。

删除：把多余的词用斜线（＼）划掉。

修改：在错的词下划一横线,并在该词下面写出修改后的词。

注意：1)每处错误及其修改均限一词;

2)只允许修改10处,多者（从第11处起）不计分。

    Guilin is in Guangxi Zhuang Autonomous Region, China, famous of its mountains and waters. I went here last summer and stayed for five day. During that time not only I enjoy the fascinating scenery like the unique mountains and clean rivers, but also I try the traditional weaving of Zhuang people. That impressed me most was the amazing folk-song-singing competition on the Li River, which attracted thousands of visitors or locals. Guilin enjoys a worldwide fame for it beautiful scenery, so it's well worth visiting. I am strongly recommend you to visit it. I believe you will have a wonderfully time.

下列关于显微镜的说法正确的是（  ）