co gia tri thuc pham

aaa  : a = 111 

vì a: a = 1 nhé

cai thang nhay quang may biet rui ma con hoi

do lam phach

la hoc sinh gioi ma hoi nhung cau nay ha nhay

Noi den hoc tro la noi den mau ao trang, mau muc tim va mau hoa phuong do.

Ngoi truong nao cung trong it nhat 1 cay phuong. Mua hoa phuong no bao hieu cho khoang thoi gian tuyet voi nhat cua hoc sinh: mua he. Sao mau la phuong, mau hoa phuong, mau than cay phuong voi sac he lai hoa hop den the!

Cai sac do ruc ro tuoi roi, min mang mot mau do, gan ve cuong canh hoa co vai dong sac trang. Khung cua so phia toi ngoi trong lop 7A nhin ra la mot tan phuong xanh ri. Tuoi tho toi da trai qua rat nhieu mua he, duoc chung kien rat nhieu mua hoa phuong no. Nhung cay phuong no do ruc nhu nhung diem 10 tren bai thi. Hoa phuong no bao hieu cho 1 ki thi day trien vong tot dep. Tuoi tre cua toi la mo uoc, la khat khao,la hoai niem. Roi toi se con thay duoc bao nhieu lan phuong no nua day!

Cu moi gio ra choi, toi thuong chay raphia san truong, nhat hoa phuong roi ve choi. Toi om ca dong hoa phuong, ngoi xuong goc cay bang yeu quy va bat dau ngam ngia. Moi hoa co 5 canh, 4 canh mau do cam mang nhung cham gach phan deu, thua va nhat dan, ve dau canh mau do dam. Canh thu5 dem lai cho hoa 1dang ve kieu sa, mem mai voi mau trang muot diem nhung vet do hai hoa. Cuong canh hoa thu 5 loang nhe mau vang ngot, dam hon mau nang ma nhe hon mau mat ong. Mot vai bong khac lai co 4 canh mau do cam, dau canh loang nhe mau rom, uot hon mau cat. Canh thu 5 lai do tuyen 1 mau doc lap. Dai hoa do phia duoi 5 canh hoa nom nhu co sao bien mat do sam, lung xanh mau chanh dang tum gon 5 canh quat duyen dang vao chinh giua. Nhi hoa gom khoang tu 5 den 10 chi nhi cham nhung bao phan sang vang rung rinh, tua tua, cong cong nhu mi mat 1 co be mo mang. Chi nhi trong nhu nhung tia mau tu nhien duoc ban len bau troi va no xoe ra o xa tit.

La phuong la loai la kep. Tau la phuong het suc nhe njhang, dap denh.La nhin xa dan xen vao voi nhau tao thanh tung chum phuong nhu mam xoi gac rai com vong. Sac xanh luc, xanh com, xanh muop, xanh sam cua la hoa voi sac do cam, vang mat, vang rom, vang cat uot, do ruc, do sam, trang... tao nen 1 khung canh vo cung lanyg mang, tho mong, em dem, xao dong.

Cay phuong cung la lung. Sac xanh la phuong kep, sac do hoa ruc ro, tuoi roi, sinh dong the ma cay lai duom ve au sau. Co le mau do hoa voi sac xanh la tuong trung cho tre con voi niem vui khi mua he den. Du he co nong, co oi mot chut, nhung dc nghi ngoi, dc di tham thu day do thi oi nong co he gi dau!

Nhung buon sau vi he den, tam xa mai truong yeu dau, tam xa ban be- bon nhoc nghich ngom, ngo ngao, lam chieu; cac thay co giao, ngoi truong, cai cong sat,cai phong bac bao ve toi cung cam thay nho, toi se buon lam khi phai chia tay chung. Co le vi the ma phuong du dep ruc ro, huy hoang la vay ma cay van duom ve au sau. Ve buon hien ra ngay tu cai ten phuong vi: kieu sa ma lang le. Hoa phuong dung la nhuoi ban an tinh cho moi the he hoc tro chumg toi.

bai nay hoc rui may con hoi an deo a nhay

Vi qua dau den va dau xanh la loai qua kho ne nen khi chung chin chung se ne ra va roi hat va ngoai va se thu hoach duoc nua

Read the following passage and mark the letter A, 8, C, or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone - a mixture of chemicals that delivers diverse messages as the context changes. These trails incorporate no directional information and may be followed by other ants in either direction.

Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.

The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space.

The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.

Question 36: What does the passage mainly discuss?

A. The information contained in pheromones

B. The mass migration of ants

C. How ants mark and follow a chemical trail

D. Different species of ants around the world