1.A
Seen from the top of the mountain,the city is very beautiful.
分析：作為條件/方式狀語,主句（主干：主系表結(jié)構(gòu)）主語為the city,是“物”,故狀語部分用“省略式”被動語態(tài)
還原完整句式（條件狀語從句）：When it is seen from the top of the mountain,the city is very beautiful.
2.C
Seeing from the top of the mountain,you will find the city very beautiful.
分析：接上,主句（主干：主謂賓+賓補(bǔ)）主語為you,是“人”,且參考其時態(tài)（will find）,系一般將來時態(tài),故考慮狀語部分用“省略式”現(xiàn)在進(jìn)行時（或：一般現(xiàn)在時）,不可用一般過去時、現(xiàn)在完成時
還原完整句式（條件狀語從句）：When you are seeing from the top of the mountain,you will find the city very beautiful.
如果說When you see from the top of the mountain,you will find the city very beautiful.
題外：考點(diǎn)1是主干與前置狀語動詞-主語一致；2是時態(tài)