29．I'm told that www．languagepractising．com is a free website ____ learners can not just learn various languages but also chat online．
| A．that | B．which | C．where | D．Whose |
—Have your read the article A Dirty Beijing, which is about air pollution?
—Yes. It’s highly informative. I _____no idea that the PM2.5 there sometimes reached 300.
| A．have | B．had | C．will have | D．would have |
—What do you think of being a volunteer, John?
—I find it a stressful job but one ___ you can really help people.
| A．where | B．which | C．when | D．that |
—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 |