_________it is true that a student’s most important goal is to do well in his or her studies, it doesn’t need to be the only goal.
| A．When | B．As | C．While | D．Before |
—Is there anything wrong, Bob? You look sad.
—Oh, nothing much. In fact , I ____ of my friends back home.
| A．have just thought | B．was just thinking |
| C．would just think | D．will just be thinking |
It is not always easy for the general public to see _____use a new invention can be of to their daily life.
| A．which | B．what | C．that | D．whose |
More highways have been built in China, ______ it much easier for people to travel from one place to another.
| A．having made | B．made | C．to make | D．making |
To her joy, Della earned first the trust of her students and then ____ of her colleagues.
| A．one | B．ones | C．those | D．that |
—How about ____ controlled breeding programme the US government began to save the red wolf?
—I should say it was ____ success, you see its number has increased
| A．a ; a | B．the; a | C．a;不填 | D．the ; 不填 |