Insects have two pairs of wings, while bats and birds each have one pair. Insect wings lack bones, but birds and bat wings have them. Butterfly wings are covered in scales, bird wings in feathers , and bat wings with bare skin.
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Answer:
By squeezing a bulb attached to the wide end of the pipette
Explanation:
You squeeze the bulb and place it on the wide end of the pipet. Then you place the tip of the pipet in the solution and release your grip to pull it into the pipet.
B is wrong, unless you want to accidentally get a mouthful of the sulfuric acid or cyanide you are pipetting.
C and D are wrong. Even the wide end of a pipette is too narrow to fill with either a beaker or an eyedropper.
Answer:
2. It is made of sandstone which is very porous and is easily penetrated by rainwater
Explanation:
The White House is made of gray-colored sandstone that is brought from quarry in Aquia, Virginia. The north and south porticos of white house building are constructed with red Seneca sandstone brought from Maryland. These sandstones are porous in which rainwater is easily penetrated in it that cause damage to the white house building so it is concluded that the building is made of porous sandstone.
