Whenever she heard that someone had trouble, she would go to ________.[ ]

Before a problem can be solved，it must be obvious____the problem itself is.

The 18th National Congress of the CPC has been one of______things in our life recently.

It is easy _____ and dance at the music festival.

I have experienced quite a number of cases ______ Ireally wanted to help but could not find anything to _______.