问题
选择题
The research mainly deals with the difficulty the students have ________ their attention on their study all
the time.[ ]
A．to focus
B．to be focused
C．focusing
D．focused
答案
答案：C
搜题请搜索小程序“爱下问搜题”
The research mainly deals with the difficulty the students have ________ their attention on their study all
the time.[ ]
A．to focus
B．to be focused
C．focusing
D．focused
答案：C
请你仔细观察下面两图，并回答问题：
 | |
| 图一 |  |
| 图二 |
（1）图一、图二分别是哪个朝代的运河？运河开凿时在位的皇帝分别是谁？
