If we make ___ best of this new equipment, there will be ___ rise in our production this year.
| A．/;/ | B．the; a | C．/; a | D．/; the |
1. — Have you known each other for long?
— Not very long, ____ we started to work in the company.
| A．after | B．before | C．when | D． since |
__________ some medals came to live in the sea is not known.
| A．Which | B．Since | C．Although | D．How |
--Nancy is not coming tonight. --But she __________!
| A．promises | B．promised |
| C．will promise | D．had promised |
__________, we'll come to see you again.
| A．If time will permit | B．Time permits |
| C．Time permitting | D．Time permitted |
The rainbow is one of the most beautiful ___ in nature.
| A．phenomenon | B．phenomenas | C．phenomena | D．phenomenons |