After several years of observation, the research group ______ the conclusion that language acquisition is faster when students ______ to the situation where it is spoken.
| A．has come to; expose | B．have arrived at; are exposed |
| C．has concluded; are exposed | D．have reached; expose |
He must be helping the old man to water the flowers, ______?
| A．is he | B．isn’t he | C．must he | D．mustn’t he |
—Can I pay the bill by check?
—Sorry, Madam, but it is our managing rule that payment ______ be made in cash.
| A．shall | B．may | C．will | D．can |
The magazine you lent me ______ among the 10 most popular ones in our school.
| A．named | B．belonged | C．listed | D．ranked |
Professor Smith, along with his assistants, ______ on the project day and night to meet the deadline.
| A．work | B．working | C．is working | D．are working |
Class regulations require ______ is the last to leave the classroom ______ off all the lights.
| A．who; should turn | B．whomever; turn |
| C．whoever; turning | D．whoever; turn |