问题
单项选择题
组成核小体的主要物质是（）
A.DNA和组蛋白
B.RNA和组蛋白
C.DNA和非组蛋白
D.RNA和非组蛋白
E.DNA和RNA
答案
参考答案：A
搜题请搜索小程序“爱下问搜题”
组成核小体的主要物质是（）
A.DNA和组蛋白
B.RNA和组蛋白
C.DNA和非组蛋白
D.RNA和非组蛋白
E.DNA和RNA
参考答案：A
| 从方框中选择合适的词,用其适当的形式填空 | |
| |
| The Channel Tunnel (英吉利海峡隧道) In 1858, a French engineer, Aim? Thome de Gamond, arrived in England with a plan for a twenty-one mile tunnel 1 the English Channel. He said that it would be 2 to build a platform in the center of the Channel. This platform 3 as a port and a railway station. The tunnel would be well-ventilated (通风好的) if tall chimneys were built 4 sea-level(海平面). In 1860, a better plan was put forward(提出) by an Englishman, William Low. He suggested that a 5 railway tunnel should be built. This would solve the problem of ventilation, 6 if a train 7 this tunnel, it would draw in (吸入) fresh air behind it. Forty-two years later a tunnel was actually begun. If, at the time, the British had not feared invasion(入侵), it would have been completed. Recently, there has again 8 great interest in the idea of a Channel Tunnel. If it 9 , it will connect (连接) Britain to Europe for the first time in 10 . |