How did all these ______?
| A．come out | B．come up | C．come across | D．come about |
While working in the countryside, the students a great deal of knowledge on plant life.
| A．looked up | B．picked up | C．put up | D．called up |
Criticism and self-criticism _____ necessary _____ it helps us to correct mistakes.
| A．is, in that | B．are, in that | C．is, in which | D．are, at that |
Running a company is not _______ a matter of hiring people — they also need to be trained.
| A．simply | B．partly | C．seriously | D．equally |
—What made ber so sad? —______a good chance to go abroad.
| A．Miss | B．Missed | C．Missing | D．Being missed |
You can come here to ask me ________ if you have any questions.
| A．at one time | B．at a time | C．at any time | D．all the time |