remain to be seen
To not yet be clear, certain, or known. We can see for ourselves the disaster's immediate impact, but the long-term environmental effects remain to be seen. Of course, it remains to be seen whether the president's popularity on other issues will carry over into this more controversial endeavor.
remain in touch
To maintain contact with another person, especially at intervals so as to stay up to date with each other's lives. My old high school friends and I tried remaining in touch after we graduated, but we all started drifting apart once college got underway. Now, make sure you remain in touch, OK? I want to hear all about your time in Paris!