—John,when will you pay a visit to that place of interest?—I can’t decide at present. _______.
Cycling is highly _____ to people’s health and the environment.
I recognize her __I met her at the airport, although we haven’t seen each other for ten years.
Unless ________ to speak, you should remain silent at the conference.
_____ in Haikou for five years, he is not used to the weather in his hometown.
________ we know, the moon goes around the sun.