'Happen' in the Bible

So I concluded that there is nothing better for a person than to enjoy [the fruit of] his labor, for this is his lot in life. {For no one knows what will happen in the future.}

For who knows what [is] good for a man in his life during the few days of his fleeting life, which are fleeting as a shadow? For who can tell anyone what will happen {in the future} under the sun?

In the day of prosperity, rejoice! But in the day of adversity, consider! For God made one in place of another so that mortals cannot find out what will happen {in the future}.

Surely no one knows what will be, so who can tell anyone what will happen?

The fool {talks too much}, for no one knows what will be. Who can tell anyone what will happen {in the future}?

Divide your share in seven or in eight, for you do not know what disaster will happen on the earth.