Carl Linnaeus made great contributions to ________ plant species.
| A．group | B．have grouped | C．grouping | D．been grouping |
When ________ to the market, these products were very popular.
| A．introducing | B．introduced |
| C．introduce | D．being introduced |
His English, ______ used to be very poor is now excellent.
| A．which | B．that | C．it | D．whom |
---- Why don’t we choose that road to save time?
---- The bridge to it _________.
| A．has repaired | B．is repaired |
| C．is being repaired | D．will be repaired |
There are many talented actors out there just waiting _______.
| A．to discover | B．to be discovered |
| C．discovered | D．being discovered |
---- Does your brother study in Beijing University?
---- No, not now. But he ________ there for 7 years.
| A．would study | B．studied | C．has studied | D．was studying |