The Greatest Mystery of Whales
The whale is a warm-blooded，air-breathing animal，giving birth to its young alive，sucking them--and，like all mammals，originated on land.There are many front flippers，used for steering and stability, are traces of feet.______of this.Its Immense strength is______into the great body of the big whales，and in fact most of a whales body is one gigantic muscle.The blue whales pulling strength has been estimated ______400 horsepower.One specimen was reported to have toweda whaling vessel for seven hours at the______ of eight knot . An angry whale will ______ A famous example of this was the fate of Whaler Essex, ______ was sunk off the coast of South America early in the last century.
More recently, steel ships have ______their plates buckledin the same way. Sperm whaleswere known to seize the old-time whaleboats in their jaws and crush Them. The greatest ______ of whales is their diving ability.The sperm whale dives to the Bottom for his______ food，the octopus.In that search he is known to go as far Down as 3,200 feet, where the.______ is 1,400 pounds，to a square inch.Doing so he Will ______ underwater long as one hour.Two special skills are involved in this storing up enough______ and tolerating the great change in pressure.Just how he does it scientists have not ______.It is believed that some of the oxygen is stored in a special______ of blood vessels，rather than just held in the lungs.And it is believed that a special kind of oil in his head is some sort of compensating mechanism that ______ adjusts the internal pressure of his body.But since you cant bring a live whale into the laboratory for study, no one knows just how these things work.
1 A aspects B signs C ways D reasons
2 A worked B divided C built D moved
3 A at B in C of D with
4 A number B degree C distance D rate
5 A abandon B attack C leave D board
6 A as B who C which D that
7 A had B operated C Seen D caught
8 A interest B job C danger D mystery
9 A favorite B fast C new D sufficient
10 A depth B pressure C level D size11 A set B become C remain D rest
12 A heat B energy C food D oxygen
13 A witnessed B determined C applied D calculated
14 A system B place C arrangement D equipment
15 A mentally B artificially C manually D automatically
答案解析：
1.答案为B。第一段讲到鲸鱼很像陆地上的哺乳动物，最后一句举了一些例子来说明这一点。 sign的意思是符号，特征，鲸鱼具有陆地上哺乳动物的一些特征，故选B。
2.答案为C。something is built into的意思是把装入，这里指鲸鱼生有 巨大的气力。其他几个选项意思上讲不通。
3.答案为A。只能用介词at，不能用其他介词。
4.答案为D。rate表示速度，从上下文来讲，选D意思才讲得通。
5.答案为B。此题亦必须根据上下文的意思来推测选哪个词。鲸鱼被惹怒后会攻击船只，所以选B。
6.答案为C。这里是一非限定性定语从句，关系代词作 主语，用which，故选C。
7.答案为A。have + something+过去分词是一固定结构，此处只能选A。
8.答案为D。本题所在句子为该段主题句，谈的是鲸鱼的潜水能力。鲸鱼的潜水能力很强，能下潜到很深的地方，科学家们不解，所以说是个迷，故选D。
9.答案为A。虽然本题的几个选项都能与food搭配，但从上下文意思来讲，只有A正确。
10.答案为B。空格后面的名词是pound，重量单位，据此可以判断选B，因为其他几个选项不能和pound搭配。
11.答案为C。呆在水下要用动词remain，其他几个动词放入空格处意思讲不通。
12.答案为D。此题也必须在读懂上下文意思的基础上才能作出判断，这里指鲸鱼聚集氧气，故选D。
13.答案为B。上文谈到鲸鱼为什么能够在水下承受巨大的压力，科学家们还没有找到答案。 选项中的deterrmine的意思是确定，此词放入空格处意思讲得通，其他几个选项讲不通，故选B。
14.答案为A。special虽然和几个选项都能搭配使用，但只有选项A意思上讲得通，故A为正确答案
15.答案为D。此题亦需根据上下文的意思作出判断。automatically的意思是自动地。