_____ he met with the difficulty did he realize the importance of group work.
| A．Even though | B．Not until | C．Only before | D．Ever since |
Don’t leave the water ___ while you brush your teeth.
| A．run | B．running | C．being run | D．to run |
The book is worth ______ a second time.
| A．to read | B．read | C．reading | D．being reading |
The last one _______ will pay the bill.
| A．arrive | B．arrived | C．to arrive | D．arriving |
Cindy seems ______her new job.
| A．content | B．content with | C．content to | D．content for |
His father died , ______his family even worse off.
| A．to leave | B．left | C．leaving | D．leave |