问题
选择题
When one makes new friends, don’t forget ______ old ones.
A．to come up with
B．losing sight of
C．to keep track of
D．keeping in touch with
答案
答案：C
come up with意思是提出、 想出 lose sight of 看不见 keep track of 保持联系 keep in touch with保持联系。有了新朋友，别忘了老朋友。故选C。