题干

关于实验变量的叙述,错误的是(    )

A:所有实验都有变量,实验变量在实验设计时就要确定

B:实验中只有一个实验变量,不能有多个

C:对照的两组,实验变量不同,其他因素相同

D:对照的两组,实验变量相同,其他因素不同

上一题 下一题 0.0难度 选择题 更新时间:2017-10-14 02:01:22

答案(点此获取答案解析)

D

同类题4

根据短文理解,选择正确答案。

    The 87th Academy Award nominations(提名)were announced on Jan 15,and The Grand Budapest Hotel stood out as a favorite with nine nominations, including Best Picture. Check out some other Best Picture nominees to see if you missed any of last year's top Hollywood films.

The Imitation Game

    This historical thriller is about British computer scientist, Alan Turing (Benedict Cumberbatch), the father of artificial intelligence. At the start of World War Ⅱ, Turing was asked to join a select team of mathematical geniuses to decode(解码)the system the Nazis used to send military messages. Besides the actual breaking of the code, Cumberbatch's portrayal(扮演)of Turing's personality, a mixture of decency(正派)and shyness, is also a highlight of the movie.

Birdman

    This dark comedy film is about how Riggan Thomson, a faded star once famous for his superhero roles, struggles to regain fame. American actor Michael Keaton, 63, who has a similar experience to Thomson's, plays the leading role.

Selma

    A stellar cast(主要演员) including talk show queen Oprah Winfrey may be one reason to see Selma. But that the film focuses on Martin Luther King Jr.'s struggle for civil rights also makes it worth viewing. Based on the 1965 Selma to Montgomery voting rights marches, the film is a chronicle(编年史) of King's(David Oyelowo) campaign for political rights for African-American people.

The Theory of Everything

    We know English theoretical physicist Stephen Hawking for his significant scientific discoveries, especially his black hole theories. This biographical film reveals the scientist's (played by Eddie Redmayne) secret romantic relationship with Jane Hawking (Felicity Jones), whom he meets and falls in love with at Cambridge and who later becomes his first wife.

Boyhood

    American Director Richard Linklater did an experiment in this film, using the same cast for l2 years to record a boy's growth. In two and a half hours, we see Mason, a Texas boy from a divorced family, grow from 6-year-old boy to a freshman in college.