He advised farmers to choose the best seed-heads ,__________ that had the best color .
| A．不填 | B．ones | C．this | D．the ones |
---- Did the judge ask you many questions? ---- Yes, and ______.
| A．they were difficult to be answered | B．to answer them was to be difficult |
| C．they were difficult to answer | D．they had difficulty in answering |
---- My baby has a heart trouble. ---- Did the doctor find it difficult ______ ?
| A．in treating | B．treating | C．for treating | D．to treat |
---- Where did he go? ---- He went to another store ______.
| A．to buy pencils | B．for buying pencils | C．buy pencils | D．buying pencils |
---- Why was the official meeting called? ---- ______ new officers.
| A．Select | B．Selecting | C．To select | D．For selecting |
Because of air pollution being greatly reduced, this city is still ______.
| A．a good place which to be lived in | B．lived as a good place |
| C．a good place to live in | D．living in as a good place |