问题 填空题

两栖动物和裸子植物是中生代地球上最繁盛的动、植物______.

答案

中生代从二叠纪-三叠纪灭绝事件开始,到白垩纪-第三纪灭绝事件为止.自老至新中生代包括三叠纪、侏罗纪和白垩纪.

中生代时,爬行动物(恐龙类、色龙类、翼龙类等)空前繁盛,故有爬行动物时代之称,或称恐龙时代.中生代的哺乳动物虽然分化成很多不同的类群,但所有这些哺乳动物都是些体型非常小的动物.中生代时裸子植物空前繁盛,有的高达数十米,到了中生代末期被子植物才逐渐繁盛.今天的煤炭石油绝大部分是中生代时期的裸子植物埋藏在地下形成的.

故答案为:×

选择题
单项选择题

To produce the upheaval (激变) in the United States that changed and modernized the domain of higher education from the mid-1860s to the mid-1880s, three primary causes interacted. The (1) of a half-dozen leaders in education provided the personal force that was needed. (2) , an outcry (呐喊) for a fresher, more practical, and more advanced kind of instruction (3) among the alumni (校友) and friends of nearly all of the old colleges and grew into a movement that overrode (压倒) all (4) opposition. The aggressive "Young Yale" movement appeared, demanding partial alumni control, a more (5) spirit, and a broader course of study. The graduates of Harvard College simultaneously (6) to relieve the college’s poverty and demand new (7) . Education was pushing toward higher standards in the East by (8) off church leadership everywhere, and in the West by finding a wider range of studies and a new (9) of public duty.

The old-style classical education received its most crushing (10) in the citadel (城堡) of Harvard College, (11) Dr. Charles Eliot, a young captain of thirty-five, son of a former treasurer of Harvard, led the (12) forces. Five revolutionary advances were made during the first years of Dr. Eliot’s (13) They were the elevation and amplification of entrance requirements, the enlargement of the (14) and the development of the (15) system, the recognition of graduate study in the liberal arts, the raising of professional training in law, medicine, and engineering to a postgraduate level, and the fostering (培养) of greater (16) in student life. Standard of admission were sharply advanced in 1872—1877. (17) the appointment of a clean (院长) to take charge of student affairs, and a wise handling of (18) , the undergraduates were led to regard themselves more as young gentlemen and (19) as young animals. One new course of study after another was (20) —science, music, the history of the fine arts, advanced Spanish, political economy, physics and international law.

11()

A.when

B.where

C.which

D.that