There are a lot of computers in the lab,and they need professional __________ to make sure they can be in a good state.
| A．operation | B．maintenance | C．service | D．advice |
The plane got back to the airport and landed＿＿＿＿at last.
| A．safe | B．safely | C．safety | D．save |
Our hall is ＿＿＿＿theirs.
| A．twice so large as | B．twice as large as |
| C．as twice large as | D．so twice large as |
—— How ＿＿＿＿＿＿＿＿ can you finish the drawing?
—— In a week.
| A．often | B．soon | C．long | D．rapid |
We decided not to climb the mountains because it was raining ＿＿＿.
| A．badly | B．hardly | C．strongly | D．heavily |
If we work with a strong will, we can overcome any difficulty, ＿＿＿great it is.
| A．what | B．how | C．however | D．whatever |