[判断题]花卉嫁接成功的要素之一就是接穗与砧木有很高的亲和。

In America and many other countries, one special kind of box contains the future. It’s called a ballot box. What people put into the box on Election Day can change the course of history.
Elections are the {{U}} (36) {{/U}} of a democracy. The word democracy {{U}} (37) {{/U}} means "the people rule", an important {{U}} (38) {{/U}} in America’s history. In America, elections are held every two years for members of Congress. In these elections, all seats in the House of Representatives and one-third of the Senate seats are up for grabs. Every four years, voters go to the polls to {{U}} (39) {{/U}} the nation’s president and vice-president. Voters also regularly vote for state and city government leaders and local school board members.
In the American electoral system, people don’t really vote for presidential candidates. Instead, voters {{U}} (40) {{/U}} their ballots for "electors" who support each candidate. Each state has as