单项选择题

A．It is nontoxic.B．It has lots of vapour.C．It doesn’t p……

Which of the following is the characteristic of hydrogen

A．It is nontoxic.
B．It has lots of vapour.
C．It doesn’t produce damaging fuels.
D．It costs less.

<上一题目录下一题>

热门试题

单项选择题It can be inferred from the passage that the Sun’s light travels ______.

A．through solid objects in space
B．in many different directions
C．more slowly than scientists previously believed
D．further in summer than in winter

单项选择题Which sentence proves that setting the giant reflector is a delicate operation

A．The first sentence in the last paragraph.
B．The second sentence in the last paragraph.
C．The last sentence in the last paragraph.
D．The last sentence in the third paragraph.

单项选择题What does the passage mainly discuss

A．The production of solar light and heat.
B．The physical and chemical nature of life.
C．The conversion of Hydrogen to helium.
D．Radiation in the X - ray part of the spectrum.

单项选择题According to the passage, in the late 1960s some residents of Boston were concerned with which aspect of skyscrapers

A．The noise from their construction
B．The removal of trees from building sites
C．The harmful effects on the city's grass
D．The high cost of rentable office space

单项选择题Where in the passage does the author compare the energy consumption of skyscrapers with that of a city

A．Lines 4 - 6.
B．Lines 7 - 10.
C．Lines 12 - 14.
D．Lines 15 - 16.