如果不确定2年前暑期研究的教授是否对我有好印象（自己认为做得不怎么样）而不请他
写推荐信的话会不好吗？（目前有2封其他专题教授推荐信，1封书报讨论推荐信）
这是我在http://ppt.cc/yeU1 看到的：
Can I send in more than 3 letters of recommendation?
Yes. Most students have to work to find 3 good letters, and those students
should certainly not send in extra. On the other hand, some students do
research in several groups and find they need more than 3 letters to give a
full picture of them and their activities. If you fail to send in a letter
from a research experience, the committee will probably assume that your
research experience went poorly.
所以对于可接受3封以上推荐信的学校，是不是不要提起那段暑期研究，还是试试看问
之前的暑期教授呢？（虽然即使她愿意我觉得可能也不会是很强的推荐信）
谢谢。。。。