听力原文： Today, Daylight Saving Time begins for most of the United States at 2 a. m. on t

he first Sunday of April. It is changed in each of the time zones across the U. S. Time reverts back to standard time at 2 a. m. on the last Sunday of October. Daylight Saving Time has been used in the United States and many European countries since World War I. It was adopted in 1918 when Congress placed the country on Daylight Saving Time to conserve energy and resources for the war effort. Between World War Ⅰ and World War Ⅱ some states and communities continued to observe Daylight Saving Time. Congress enacted The Uniform. Time Act of 1966 and Daylight Saving Time became observed nationally.

Even though Congress enacted the !aw, the law does not require that Daylight Saving Time be observed. It only states that if is observed then Daylight Savings Time must be done so uniformly. In the U. S. and its territories the following do not observe Daylight Saving Time: Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands. The Eastern Time Zone portion of the State of Indiana, and most of Arizona with the exception of the Navajo Indian Reservation in Arizona.

Daylight Saving Time begin at 2 a. m. ______ in the United States every year.

A．on the last Sunday of April

B．on the first Sunday of April

C．on the last Sunday of May

D．on the first Sunday of May