29.It is required in a recent study suggesting the importance of teenagers’ communication with other children of the same age.
Only by ______ your attention _____ what you are learning can you learn it well.
How proud she is! She has been ________ Beijing University.
I used to quarrel a lot with my parents, but now we ________ well.
---- She looks happy. She ________ have passed the exam. ---- I guess so. It’s not difficult after all.
Scientists have to work hard to keep ________ with modern discoveries and developments.