重点讲解：
1. at present 目前；现在；眼下；
There are at present four television channels.
现在有四个电视频道。
2. rule out 排除；不予考虑；
I can't rule out the possibility of trouble.
我不能排除遇到麻烦的可能性。
3. under control 得到控制；
The fire is still burning but it's under control.
大火仍在燃烧，但已经被控制住了。
4. keep up with 跟上（变化等）；
If you want to keep up with the times, you have to get a large amount of information.
如果你想跟上时代，你必须获取大量的信息。