ESV: I have seen the business that God has given to the children of man to be busy with.
NIV: I have seen the burden God has laid on the human race.
NASB: I have seen the task which God has given the sons of mankind with which to occupy themselves.
CSB: I have seen the task that God has given the children of Adam to keep them occupied.
NLT: I have seen the burden God has placed on us all.
KJV: I have seen the travail, which God hath given to the sons of men to be exercised in it.
NKJV: I have seen the God-given task with which the sons of men are to be occupied.