The UN system is a major purchaser of goods and services ,_______over $4 billion a year .
| A．to total | B．totaling | C．totaled | D．total |
__________ medical science has achieved control over several dangerous diseases, what worries us is that some of them are returning.
| A．Since | B．Unless | C．However | D．Although |
I remember __________ the factory owned a small workshop and two machines.
| A．when | B．how | C．whether | D．what |
She has been teaching in a school since she graduated, so she is not __________ to associating with business people.
| A．addicted | B．devoted | C．accustomed | D．admitted |
__________ a certain doubt among the workers as to the necessity of the work.
| A．There existed | B．It existed | C．There had | D．It had |
—She couldn't have done that sort of thing.
—Whatever she did was reasonable, __________ to what you did.
Besides, it, s none of your business. Get down to __________ your lessons.
| A．comparing; doing | B．comparing; do |
| C．compared; doing | D．compared; do |