9/ I'd lost my key, so I ____ the door when I got home. a. could lock b. wasn't able to lock c. couldn't unlock d. was able to unlock 10/ When Mr. Lee was younger, he ____ work in the garden for hours. a. has got to b. should be able to c. can d. could 11/ Since they came, we _____ able to work on the project. a. are b. have been c. have to be d. were 12/ Despite the bad weather, he ____ get to the airport in time. a. could b. was able to c. couldn't d. might 13/ Robert ____ a new car for a very good price. He paid 30 percent less than the regular retail cost. a. could buy b. was supposed to buy c. had to buy d. was able to buy

9/ I'd lost my key, so I ____ the door when I got home.

a. could lock

b. wasn't able to lock

c. couldn't unlock

d. was able to unlock

10/ When Mr. Lee was younger, he ____ work in the garden for hours.

a. has got to

b. should be able to

c. can

d. could

11/ Since they came, we _____ able to work on the project.

a. are

b. have been

c. have to be

d. were

12/ Despite the bad weather, he ____ get to the airport in time

 a. could

b. was able to

c. couldn't

d. might 

13/ Robert ____ a new car for a very good price. He paid 30 percent less than the regular retail cost.

a. could buy

b. was supposed to buy 

c. had to buy

d. was able to buy

@Moon

Chúc bạn học tốt! Mong bạn rate 5 sao, cho mình "cảm ơn" và ctlhn nhé! (làm ơn cho mình ctlhn đi mà, mình cần cho nhóm T^T )