Please _____ any change of your address as soon as possible

The weather was ______ cold that I didn’tlike to leave my room.

_____ was very ____ that little Jim wrote the letter

Qian Xuesen tried many times _________ he found thesolution to the puzzle about space technology.

＂Wechat＂(微信) really makes a great __________ to people’s life. It’s easy for us to keep in touch with others.