b.I didn't do the washing last week . I did the washing yesterday

c. We didn't have a shower every day. We had a shower every 3 days.

d. They didn't return home last night. They returned home early last night.

e. Hoa didn't live in Ha Noi last year. She lived in Hue.

f. Mr. Ha didn't teach Geography. He taught English.

g. Liz didn't eat fish. She ate noodles instead.

h. My mother didn't iron my clothes. I ironed my clothes myself

b)Did they play table tennis after school ? c)Did you have a big breakfast this morning ? d)Did Hoa receive a lot of letters from his pen pal ?

e)Did you change clothes every 3 days ?

f)Did they speak to Liz yesterday ?

Một phễu đựng kem hình nón bằng bạc có thể tích 12 π (cm³) và chiều cao là 4 cm. Muốn tăng thể tích kem trong phễu hình nón lên 4 lần nhưng chiều cao không thay đổi thì diện tích miếng giấy bạc cần thêm là

A .   ( 12 13   -   15 ) π   ( cm 2 )

B .   12 π 13   ( cm 2 )

C .   12 13 15   ( cm 2 )

D .   ( 12 13   +   15 ) π   ( cm 2 )

Số electron tối đa chứa trong các phân lớp s, p, d, f lần lượt là

A. 1; 3; 5; 7

B. 2; 6; 10; 14

C. 2; 8; 18; 32

D. 2; 8; 14; 20