There are many answers in the sixth section of the second chapter in the seventh grade of science

There are many answers in the sixth section of the second chapter in the seventh grade of science

D A A B D C D D B A
11. The species are classified according to their characteristics
12. Organisms have stress, can grow, can reproduce, need nutrition, have cell structure, can heredity and variation, can metabolize
13. Animals absorb nutrients from the outside world, and plants use photosynthesis to produce nutrients
14. They all have nuclei
15. It has three pairs of feet and two pairs of wings. The body is divided into head, chest and abdomen
16. A: cover the slide again. C: take the material from the clean mouth
D: the scraping material should be evenly smeared in normal saline
17. (1) weeping willows, grass, birds and earthworms
(2) Animals and plants get nutrition in different ways (3) listening errors
18. (1) is "bighead" a fish or a mammal
(3) Evidence from villager A: the body is fish shaped, 2.5 meters long, with underdeveloped eyes, living in the water
Evidence from villager B: it has heart, lung, stomach, liver, intestine and other organs, similar to human beings, and also harbors dead larvae
19. (1) is Tenebrio molitor eating plastic? Tenebrio molitor can eat plastic
(2) she divided the Tenebrio molitor into two groups A and B, and two groups of worms were designed "recipes". The first group fed wheat bran, while group B reduced the bran and vegetable leaves, and gradually increased the foam plastic box.
(3) Properly raise some Tenebrio molitor to deal with white pollution

Chapter 2 Section 2 mechanical movement (2) answers

1. The front is short 2. The speed of movement is meter / second meter / second unit time
3. A the time used in the same journey e the journey speed passed at the same time
4-8: acaca 9. Is 25 13.3 8
10. No, the journey is different in the same time
The average speed of the car in the last 20 km is 30 km / h
11.A

Vision of the eye (1) 11~
I'll give you points

1、 Thick
The smallest and brightest spot
Convergence
focus
focal length

About percentage application!
The oil import volume of an oil importing country this month is 5% lower than that of last month. Due to the rise of international oil price, the cost of oil import this month is 14% higher than that of last month. So, the growth rate of oil price to that of last month is 5%_______ .
[I won't do it, but I know the answer is 20% with why,

① The oil import volume of an oil importing country this month is 5% lower than that of last month
This sentence is a fraction sentence, and then find out "last month" from the comparison. We get that last month was "unit one", so this month is 1-5% = 95%!
(hint: when I start, I can find out the sentences with score rate first, and then find out the sentence after "yes" or "Bi" from "yes" or "Bi". This is unit one.)
② On the contrary, the cost of importing oil this month is 14% higher than that of last month
This sentence is still a fraction sentence (I am not a bit wordy? Ha ha), from the "than" can be seen, unit one is still "last month", we come to two sentences, unit one is unified, so it is convenient for us to do the following questions. Then, compared with unit one increased by 14%, that of course is 1 + 14% = 114%!
(hint: first make sure whether unit one is unified or not, otherwise it will cause unnecessary errors, and pay attention to the corresponding quantity rate.)
③ What is the effect of oil price on the growth rate of last month?
Now it's time to start with the question. He asked whether it was the rate of growth or the rate of growth. So we used 114 △ 95 = 1.2 (120%), and only used 100% to buy oil last month, so 120% - 100% = 20%
Is that OK?

It's practice 12,

Where are you from

The school assigned the task of planting 70 trees to each class according to the number of students in three classes of grade 6. There were 46 students in class 1, 44 students in class 2 and 50 students in class 3. How many trees should each class plant?

The total number of trees planted in three classes: 46 + 44 + 50 = 140 (shares), the number of trees planted in one class: 70 × 46140 = 23 (shares), the number of trees planted in two classes: 70 × 44140 = 22 (shares), the number of trees planted in three classes: 70 × 50140 = 25 (shares). A: 23 trees planted in one class, 22 trees planted in two classes, 25 trees planted in three classes

Page 49 first
There were 303 new born babies in an obstetrics and gynecology hospital last month, and the ratio of male to female babies was 51:50?

303 / (51 + 50) = 3 (people) 3 * 51 = 153 (people) 50 * 3 = 150 (people), 150 women and 153 men
Our teacher said it, and we promise it's right

Sixth grade mathematics volume I exercise every lesson
The time from 12 noon to the end of the first class in the afternoon is one third of the time from the end of the first class in the afternoon to 12 midnight. Please calculate the time of the first class in the afternoon

Take the time from 12:00 noon to 12:00 midnight as unit 1, that is, 12:00 noon is 0. Thus, assume that the time of the first class in the afternoon is x, and get the equation
1 / 3 * (1-x) = x; the solution is x = 0.25

Do the seventh question on p55 in math lesson 1 of grade 6
When we deduce the formula for calculating the area of a circle, we need to piece the circle into an approximate rectangle, as shown in the figure below on the left
The figure is an approximate rectangle with a width of 3cm
(1) In the figure, 3cm is approximately rectangular: it is the original circular
(2) How many centimeters is the length of the cut rectangle?
(3) What is the area of the original circle in square centimeter?

The length of the rectangle is π R and the width is r
In the figure, 3cm is the width of an approximate rectangle and the radius r of the original circle
The length of the cut rectangle is 3.14 × 3 = 9.42 cm
The area of the original circle is: 3.14 × 3-178; = 28.26 square centimeters

Pear 3, Apple 2, (): () = 1 / 3

Pear 3, Apple 2, (1): (3) = one third
1 apple: 3 pears = 1:3 = 1 / 3