句子功能题（function of the sentence）属于ACT语法中特有的一种题型，出题形式是在文中划线，题目一般问如果把文中划线部分去掉，段落会失去什么。
例子：
We have long known that ancient Egyptians sailed the freshwater Nile River. However, until Wadi Gawasis was excavated, there had been little evidence that [3] we had also sailed the ocean. [B] Hieroglyphic inscriptions suggested that some of the excavated objects had been used in an expedition to the ancient Red Sea port of Punt about one thousand miles from Wadi Gawasis. Planks pocked with holes bored by shipworms, [4] creatures that live only in salt water, supported the hypothesis that ancient Egyptians had ventured into the ocean.
4. If the writer were to delete the underlined portion (adjusting the punctuation as needed), the paragraph would primarily lose an explanation of why:
F. evidence of shipworms could indicate that the Wadi Gawasis ships had sailed the ocean.
G. archaeologists thought Punt was the destination of the Wadi Gawasis expedition.
H. shipworms may have bored holes in the planks of the Wadi Gawasis ships.
J. there was evidence of shipworms at Wadi Gawasis.
答案解析
此题选F。首先原文中划线部分是前面shipworms一词的同位语，如果不看划线部分Planks pocked with holes bored by shipworms…supported the hypothesis that ancient Egyptians had ventured into the ocean. 意思是船板上布满了船虫钻出的洞，这支持了古埃及人曾冒险进入海洋的假设，那么读者很容易产生疑问：为何有这些洞就能证明古埃及人到过海洋呢？因此划线部分其实提供了一种解释，即这些船虫只生活在盐水中，由此可以判断出F选项正确。句子功能题一定要把划线部分结合上下文的语境判断，干扰项往往只含有一些相关用词但从逻辑上看并不成立，因此比较容易排除。 |
