1. Unlike most of the world's volcanoes, they are not always found at the boundaries of the great drifting plates that make up the earth's surface; on the contrary, many of them lie deep in the interior of a plate.

【譯文】和世界上大多數(shù)火山不同的是，它們并不總是在構成地球表面的巨大漂流板塊之間的邊界上出現(xiàn)；相反，許多熱點處于板塊較深的內(nèi)部。 

【析句】這是一個由兩個分句組成的并列句，中間由分號隔開。在前一個分句中， Unlike most of the world’s volcanoes是一個形容詞短語，修飾句子的主語they。定語從句（that make up the earth’s surface）修飾the great drifting plates。第二個分句結構較簡單，注意many of them是指many of the hot spots。

【講詞】make up意為“化妝；補足；拼湊；組成；編造”等。He made up an excuse for his absence in class, which was found out.（他編了一個借口沒來上課，結果被發(fā)現(xiàn)了。）I’ll make up the difference in the bill.（我來補上帳單的差額。）You have to make up the lost time by studying harder.（你應該更加努力學習，以彌補失去的時間。）He kissed his wife and made up with her.（他吻了妻子，和她和好了。）

2. The complementary coastlines and certain geological features that seem to span the ocean are reminders of where the two continents were once joined.

【譯文】 互相吻合的海岸線和某些似乎跨越海洋的地質特征會使人想到這兩個大陸曾經(jīng)是連在一起的。

【析句】 這個單句的主語是the complementary coastlines and certain geological features，后面跟了一個定語從句（that seem to span the ocean），從句中that充當?shù)氖侵髡Z。全句的表語名詞reminders跟了一個of短語結構，其中包含一個表示地點的從句。

【講詞】 reminder的意思是“暗示；有提醒作用的人或物”。The museum serves as a reminder of the crimes committed against the people of Nanjing.（紀念館提醒人們不要忘記南京人民所遭受的暴行。）

span作名詞表示“跨度；范圍”，作動詞時意為“橫越”。Richard Carleton, an award-winning journalist whose career in Australian television spanned 40 years, died on Sunday.（理查德·卡爾頓星期天去世，這位多次獲獎的記者曾在澳大利亞的電視機構工作了40年。）The Thames is spanned by many bridges. （泰晤士河上架設了許多橋梁。）