Gửi đc rồi thây -_-
Câu 1: Vì sao tự thụ phấn ở cây giao phấn và giao phối gần ở động vật qua nhiều thế hệ có thể gây ra hiện tượng thoái hóa? Lấy VD bằng sơ đồ lai.
Câu 2: Ánh sáng có ảnh hưởng thế nào đối với đời sống sinh vật ( thực vật và động vật).
Câu 3: Cho ví dụ một chuỗi thức ăn có bốn mắt xích.
Câu 4: Thế hệ xuất phát kiểu gen là AaBb tự thu phấn liên tiếp thì tỷ lệ dị hợp của hai cặp gen của thế hệ F4 là bao nhiêu? Biết hai cặp gen phân li độc lập nhau.
Câu 1: Máy biến áp có U1 =220V,U2 =24V và số vòng cuộn thứ cấp n2 =460 vòng.
a, Tính số vòng dây cuộn sơ cấp. ?
b, Mày biến áp là máy tăng áp hay giảm áp? Tại sao?
c, Nếu hạ U1 xuống còn U1=150 V, U2 giữ nguyên thì số vòng n2 thay đổi như thế nào?
Câu 2: Thấu kính phân kì có vật AB cao 2 cm, tiêu cự có khoảng cách 8 cm, khoảng cách từ vật đến thấu kính là 12cm.
a, Vẽ ảnh A’B’.
b, Tính chiều cao của ảnh và khoảng cách từ ảnh đến vật?
Cảm ơn ạ
I. Make sentences. Put the verbs into the correct form: the past simple or the past progressive.
1. While I/write/letter/phone/ring.
2. you/read/newpapers/as soon as it/arrive?
3. she/not lock/ door/when she/leave/office.
4.train/go through/tunnel/when/it suddenly/stop.
5.she/wash/hair/when/doorbell/ring.
6. Joln Logie Baird/invent/television/or/telephone?
7. they/cry/when/they/hear/bad news.
8. eat/lie/on/sofa/when/mouse/come into/room.
II. Write sentences, beginning with" I wish".
1. I hate having to wear my crash helmet whenever I ride my motorbike to school.
2. I'm not used to the noise in this city.
3. I don't have a bigger dictionary.
4. It's a pity that my room is too small.
5. I don't know anyone in this class.
6. It's a pity that Lan can't come to my birthday party.
7. The dictionary is more than I can afford.
8. The bus stop is far from where I live.
9. I have to stay at home every Sunday night.
10. It's very cold in the winter here.
III. Complete the second sentences, using the word in bold. You must use between two and five words, including the words given.
1. I'm sorry I can't speak English perfectly.
wish......
2. I'm sorry I can;t do this exercise.
only
3. I'm sorry I don't know how to swim.
only
1. Join the pairs of sentences using ralative clauses.
1. She knows somebody. The person can sing very well.
2. This is the house. My father likes the garden of the house.
3. The teacher punished the student. This student was naughty.
4. She sell in love with a man. The man was from another country.
5. I like to write to friends. These friends are living far away from me.
6. I bought some pencils. They are in differet colours.
7. Peter chose the oldest violin. The violin was in a junk shop.
8. She ate an apple. The apple was still green.
9. This is my beloved school. I studid in this school when i was young.
10. I alway bear in mind my childhood. During this time I could run around picking up flowers and chasing butterflies.
II. Change these sentences using the expressions in brackets.
1. Mike will not go with Mariam even though he likes her. (in spite of )
2. In spite of their mother's unhappiness, they held a party.
- CÁC BẠN CÓ BIẾT BÀI TẬP NÀY Ở SÁCH NÀO KHÔNG ?
1. Rewrite the following sentences so that the second sentence means exactly the same as the sentence before it. One example has been done for you.
a. I like table tennis and that's why i spend a lot of time on that game.
b. Because the weather was cold, we had to cancel our picnic
c. I won't forget to phone her. You know, I like her so much.
d. They tried their best to complete the course and that was why they passed it.
e. I love my city so much, so i think i will stay and work here in my city.
f. He doesn't see any reasons for a holiday, therefore he will continue to work.
h. Please don't forget me beacause i will miss you so much.
i. The children like cartoons so much, so they will ask their grandpa to by cartoons for them.
2. Change the following indirect statements into direct statements. One example has been done for you.
a. The teacher told his students that he would be busy the following month.
b. Mum told me that she was sad then.
c. One of my friends said that he liked learning English with his teacher
d. The doctor told me that i could leave the hospital that day.
e. The landady told me that i could use those bed covers.
f. The gardener said that those flowers were not very fresh in that garden.
g. The stamp collector said that he was collecting stamps because he would attend a stamp contest the following year.
h. The film director said that she was wiling to work then.
3. Make sentences based on the given cues. One example has been done for you.
a. Students/said/they/not/happy/hear/news.
b. The teacher said/students/had follow/school plan.
c. They /had/work/hard/during/Christmas.
d. She/said/she/not/ready/examination.
e. Other students/said/they/happier/if/teacher/delay/exam.
f. The teacher said/time/not/changed.
g. All students/made/sad/news.
h. One of/students/told/teacher/it/Christmas/following week.
4. Tìm lỗi sai trong các câu sau nếu câu đó đúng đánh tích vào phần cuối câu ( Viết tiếng anh hơi dài neeh mk vt tiếng việt)
a. They are so naughty children that their mother can't stand them.
b. He eats so many food that he gains weight quickly.
c. I don't like meat but i don't eat it.
d. What are you going to do in Christmas.
e.She has helped so many people that she can't remember how many people she has helped.
f. I wish you could helping me with my homework.
g. There are so little sugar that i can't make coffee.
h. She had a walk with her dog on a beautiful afternoon.
i. The bicycle is such old that i don't want to use it.
k. The film is so interesting that the children insist on buying it.