6. Don't ________ a new business field without having done extensive homework – or preferably having worked in the field.
举一反三
- ____ in this field for nearly 10 years, Mark has lots of experience and is fit for the position. A: Having worked B: Worked C: To have worked D: Have worked
- As we have an extensive business connection in this field,we hope ______ your special terms.
- _____ in the company for three years, Mark has become experienced in business negotiations. A: Having worked B: Having been working C: Have worked D: Worked
- He doesn't do his homework every day. ---- His homework ______ by him every day. A: doesn't be done B: aren't done C: don't be done D: isn’t done
- If F is a vector field, then divF is a vector field.