The plane takes off at 6:00 p.m. So I have to arrive at the airport ________ 5:30 p.m. at the latest.A after B. since C. until D. by
—Have you got any particular plans for the coming holiday? —Yes.________,I'm going to visit some homes for the old in the city.
—Who should be responsible for the accident? —The boss,not the workers.They just carried out the order ________.
The shocking news made me realize ________ terrible problems we would face.
—What's the matter with Della? —Well,her parents wouldn't allow her to go to the party,but she still ________.
________ a certain doubt among the people as to the practical value of the project.