42,648 免费图片适用于学生

生物学水下海上生活鱼海洋动物野生动物水海洋

Alewife-3

Bluegill on nest-1

Redear sunfish school with other species of sunfish

Shark Fish

Brook trout-3

Brook trout-1

Brook trout-2

Brook trout-2

Bluegill on nest-7

Sea turtle release after the cold weather.

Male bowfin hides in vegetation-4

Shipwrecked ruins in the Bahamas

(Martine) Nurse is Using a Pointer

Cameron Indoor Stadium with student tents at Duke University, North Carolina

Mouth

医疗药物科学

Hand is Holding a Toothbrush

工具类浴室

School girl

孩子们学校

Motivated Student Girl

Student Girl

Male Student in Love

Student Boy Cries in Depression

失望的学生

Smiling Dinosaur

Medical Doctor

Cicada

South America

南美洲大洲

Neuron

神经元健康

Chromodoris Willani Nudibranch

Redear sunfish-1

Bluegill on nest-3

Ash Meadows Amargosa pupfish-1

Close-up of Redbreast Sunfish-4

(Trevor) Surgery Medical Doctor

护理人员医生

A technician placing the repackaged influenza samples into a cold–storage environment within the laboratory setting. Original image sourced from US Government department: Public Health Image Library, Centers for Disease Control and Prevention. Under US law this image is copyright free, please credit the government department whenever you can”.

Novel Coronavirus SARS-CoV-2–This scanning electron microscope image shows SARS-CoV-2—also known as 2019-nCoV, the virus that causes COVID-19. Original image sourced from US Government department: The National Institute of Allergy and Infectious Diseases. Under US law this image is copyright free, please credit the government department whenever you can”.

显微镜健康

Biologist monitors aquatic plants-2

A 440X photomicrograph magnification of a hematoxylin and eosin (H&E)–stained liver tissue specimen, revealed the presence of cytoarchitectural changes indicative of fatty degeneration. Original image sourced from US Government department: Public Health Image Library, Centers for Disease Control and Prevention. Under US law this image is copyright free, please credit the government department whenever you can”.

实验室细菌

A 3D graphical representation of a number of norovirus virions, set against a black background. Original image sourced from US Government department: Public Health Image Library, Centers for Disease Control and Prevention. Under US law this image is copyright free, please credit the government department whenever you can”.

MERS Coronavirus Particles–Colorized scanning electron micrograph of MERS virus particles (yellow) both budding and attached to the surface of infected VERO E6 cells (blue). Original image sourced from US Government department: The National Institute of Allergy and Infectious Diseases. Under US law this image is copyright free, please credit the government department whenever you can”.

显微镜藍色

Medical Doctor Nurse Patient

Biologist searches for freshwater mussels

Bluegill on nest

Biologists search for Fountain Darter-1

Operation at Herrin Hospital (private), Herrin, Illinois (1939).

Fish Bone 2

Brook Trout in Aquarium - Salvelinus fontinalis

Ash Meadows Amargosa pupfish-4

Bluegill on nest-1

Texas Cichlid - Herichthys cyanoguttatus

Young brook trout with fall leaves in water-2

Redbreast sunfish-1

Ash Meadows Amargosa pupfish-1

Young brook trout with fall leaves in water-1

Bluegill on nest-1

Rock bass-1

Ash Meadows Amargosa pupfish-1

Skeleton Foot

医疗药物科学

Queen angelfish

Brook trout-5

Redline darter

Lake chubsucker

Redbreast sunfish-1

Redbreast sunfish-2

Redbreast sunfish-3

Striped mullet school swims over vegetation-3

Giant Panda is Hiking

徒步旅行熊猫

Grape Leaf

Schoolboy Study a Difficult Subject

Open Books

Greenery green space crops

Sockeye Salmon-1

Chinook salmon-1

Alewife-1

Preparing to tag black bear cub

野生动物哺乳动物

Female Teacher

Boy is playing table tennis

Toothbrush and Toothpaste

玻璃容器浴室

Shrimp in water

Dead salmon on Russian River

Slimy sculpin-3

Brook trout in Seneca Creek-5

Sockeye Salmon-1

Sockeye Salmon-1

Male bowfin hides in vegetation-3

A Petri dish culture plate, which had contained a growth medium of sheep blood agar (SBA), and which was inoculated with Gram–positive, Burkholderia pseudomallei bacteria. Original image sourced from US Government department: Public Health Image Library, Centers for Disease Control and Prevention. Under US law this image is copyright free, please credit the government department whenever you can”.

Florida bluegill

Allegheny Crayfish-2

Striped mullet school swims over vegetation-1

Largemouth bass-2

Pink Petaled Flowers Selective Focus Photography

Pom Pom

Male Teacher

Home Education

孩子们背景

Student workplace

电子计算机图书

Receptionist Woman in Thought

Toothbrush and Toothpaste

玻璃容器浴室

大學生

Bluegill on nest-2

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