Jack could have avoided that terrible car accident, but he ________ careful enough.

––Oh, it’s you! I          you. ––I’ve just had may hair cut and I’m wearing new glasses.

---What ‘s the matter with you? --- You _____ my heart. - -- But I didn’t mean to hurt you.

Before ___ a loan ____, calculate (核算) your monthly costs.

We were told not to touch the equipment in the laboratory unless ________.