Cho tam giác ABC có BC=7cm; góc ABC=42 độ, góc ACB=35 độ. AH là đường cao. TÍnh độ dài AH

Cho tam giác ABC cân tại B, trung tuyến AD vuông góc với phân giác CE. Tính cos góc ACB?

Giúp em với, em cảm ơn :<

Phép tính sau ĐÚNG hay SAI ?

Mark the letter A,B,C or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.

 The demand was so great. They had to reprint the book immediately.

A. They demanded that the book be reprinted immediately.

B. So great was the demand that they had to reprint the book immediately.

C. The book would be reprinted immediately since the demand was great.

D. They demanded to reprint the book immediately

My mother advised me _____ an apple every day to stay healthy.

A. eat

B. ate

C. eating     

D. to eat 

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

Any change in one part of an ecosystem can cause changes in other parts. Droughts, storms and fires can change ecosystems. Some changes (1) _______ ecosystems. If there is too (2) _______ rainfall, plants will not have enough water to live. If a kind of plant dies off, the animals that feed on it may also die or move away. Some changes are good for ecosystems. Some pine forests need fires for he pine trees to reproduce. The seeds are sealed inside pinecones. Heat from a forest fire melts the seal and lets the seeds (3) _______. Polluting the air, soil, and water can harm ecosystems. Building (4) _______ on rivers for electric power and irrigation can harm ecosystems around the rivers. Bulldozing wetlands and cutting down forests destroy ecosystems. Ecologists are working with companies and governments to find better ways of (5) _______ fish, cutting down trees, and building dams. They are looking for ways to get food, lumber, and other products for people without causing harm to ecosystems.

Điền vào ô số 1

A. harms    

B. harmful   

C. harmless 

D. harm