In the United States there are, strict speaking, no national __1__
holiday, for each state must, through legislative enactment or __2__
executive proclamation, appoint the day which each holiday is __3__
celebrated. Congress and the president may establish legal holidays
for the District of Columbia and for federal employees throughout
the states and territories; and by long custom, days that receive
nationwide observation, such as Christmas, Thanksgiving, Labor __4__
Day, Independent Day, and New Year’s Day, are uniformly set __5__
apart by all states as legal, or public holidays. In 1968, federal __6__
legislation established Columbia Day as a legal holiday for the
District of Columbia and for the federal government beginning at __7__
1971. The law also provided begun in 1971 federal employees __8__
would be granted three-days weekends by observing Washington’s __9__
Birthday on the third Monday in February, Memorial Day on the
last Monday in May, Columbus Day on the second Monday in
October, and Veteran Day on the forth Monday on October. By
1971, most of the states also adopted the new dates. __10__

参考答案及解析:
1.strict改为strictly

2.holiday改为holidays
因为原句的谓语动词为复数are，所以holiday必须使用复数。另外no后面可以用复数也可以用单数。

3.which前面加上on
因为先行词the day在关系从句钟做状语，还原回去应为：each holiday is celebrated on the day，所以必须加on。

4.obsevation改为observance
observation意思为“观察，观测”，observance则表示“遵守，庆祝”。

5.Independent改为Independence
独立日的说法是“Independence Day”。

6.apart改为aside
set apart 指“使分离，使分开”，语义不同，set aside表示“留出，保留”的意思。

7.at改为in

8.begun改为beginning
动词begin和分句的主语federal employees的关系是主动的，应此要用beginning。

9.three-days 改为three-day
用连字符连接起来的表示数量的名词的前置修饰语的复数概念仍然是单数，如：
a million-pound banknote。

10.also前面加had
如果一个句子里面有by引导的时间状语从句则动词一般用完成体。