[单项选择]We are living in an age ______ many things are done on computer.
A. which
B. that
C. whose
D. when

[单项选择]We are living in an age ______ many things are done on computer.
A. which
B. that
C. whose
D. when

[单项选择]Which living things can use sun energy directly
A. Animals.
B. Plants.
C. Both animals and plants.
D. All living things.

[单项选择]The respiration of living things and the food production of plants are ______.
A. separate processes
B. complementary
C. opposite
D. interdependent

[单项选择]According to the writer, living things on Earth have included ______.
A. atoms and molecules
B. chemicals
C. plants, fish, dinosaurs and human beings
D. the primitive soup

[单项选择]

Bacteria (细菌) are extremely small living things. While we measure our own sizes in inches or centimeters, bacterial size is measured in microns. One micron is a thousandth of a millimeter: a pinhead is about a millimeter across. Rod-shaped bacteria are usually from two to four microns long, while rounded ones are generally one micron in diameter. Thus, if you enlarged a rounded bacterium a thousand times, it would be just about the size of a pinhead. An adult human magnified by the same amount would be over a mile (1.6 kilometers) tall.
Even with an ordinary microscope, you must look closely to see bacteria. Using a magnification of 100 times, one finds that bacteria are barely visible as tiny rods or dots. One cannot make out anything of their structure. Using special stains, one can see that some bacteria have attached to them wavy-looking "hairs" called flagella. Others have only one flagellum. The flagella rotate, pushing the bacteria through the water. Many
A. A rider jumping on a horse's back.
B. A ball being hit by a bat.
C. A boat powered by a motor.
D. A door closed by a gust of win

[单项选择]There are a lot of small living things in the sea,and they live by eating fishes.

[单项选择]Without water ______ living things could survive.
A. no
B. anything but
C. no one
D. nothing but