234. After the 1911 Revolution, China began to use the Gregorian calendar (solar calendar) and at the same we have also used the lunar calendar(阴历) in which a leap year (闰年)______ every four years.
—Is your husband good at cleaning up the room? —Not very,but when it ________ cooking,he is much better than I am.
I think Jack will ________ a good monitor,so I’d like to vote for him.
The little boy was so careless with his spelling that he often ________ letters from words.
Evidence obtained from observation and experiment is often used to ________ a scientific theory.
.Faced with a problem,you have to ________ it first,and then try to find a solution.