Of the six outer planets, Mars, commonly called the Red Planet, is the closest to Earth. M

For many years, Mars had been thought of as the planet with the man made canals, supposedly discovered by an Italian astronomer, Schiaparelli, in 1877. With the United States spacecraft Viking I's landing on 'Mars in 1976, the man-made canal theory was proven to be only a myth.

Viking I, after landing on the soil of Mars, performed many scientific experiments and took numerous pictures. The pictures showed that the red color of the planet is due to the reddish, rocky Martian soil. No biological life was found, though it had been speculated by many scientists. The Viking al so monitored many weather changes including violent dust storms. Some water vapor, polar ice and permafrost were found, indicating that at one time there were significant quantities of water on this distant planet. Evidence collected by the spacecraft shows some present volcanic action, though the volcanoes are believed to be dormant, if not extinct.

Which of the following is true？

A．Mars is larger than the Earth.

B．Mars had Viking as its moon.

C．Martian soil is brownish rod.

D．It takes longer for Mars to circle the Sun than it takes the Earth.

A. The inner query always sorts the results of the outer query

B. The outer query always sorts the results of the inner query

C. The outer query must return a value to the outer query

D. The inner query returns a value to the outer query

E. The inner query must always return a value or the outer query will give an error

A.DECLARE x char(10) DEFAULT 'outer '

B.DECLARE x char DEFAULT 'outer '

C.DECLARE x char(10) DEFAULT outer

D.DECLARE x DEFAULT 'outer '

outer space in human history.

A.historian

B.history

C.historic

D.historical

Cosmic ( 宇宙的) rays of various kinds come __________ the air from outer space

[A] across

[B] to

[C] from

[D] through

样式表定义.outer{background-color:yellow}表示网页中某一个id为outer的元素的背景色是红色的。()

A.网页中某一个id为outer的元素的背景色是红色的

B.网页中含有class=”outer”元素的背景色是红色的

C.网页中元素名为outer元素的背景色是红色的

D.以上任意一个都可以

A.SELECT * FROM erexam NATURAL LEFT OUTER JOIN exampaper;

B.SELECT * FROM erexam NATURAL LEFT JOIN exampaper;

C.SELECT * FROM erexam NATURAL JOIN exampaper;

D.SELECT * FROM erexam OUTER JOIN exampaper;

E.SELECT * FROM erexam NATURAL OUTER JOIN exampaper;

F.SELECT * FROM erexam LEFT OUTER JOIN exampaper;