Exploring _____space is exciting, yet dangerous.
There is _____need for both robots and humans for space exploration.
| A．the; a | B．a; a | C．/; a | D．/; the |
It’s the __ job he’s ever done.
| A．bad | B．badly | C．worse | D．worst |
A train can run __ a bus.
| A．so quickly than | B．quickly than | C．as quickly | D．more quickly than |
Here are three balls, ___?
| A．which one is the bigger | B．what ball is the bigger | C．which one is the biggest | D．what ball is biggest |
__ you study, ___ you will learn.
| A．Harder….harder | B．The more… the harder | C．The hard.. the more | D．The harder.. the more |
He goes there __ than I .
| A．often | B．more oftener | C．more often | D．as often as |