Exercise 5 1 Tom said to the girl: "When did you have this picture taken?" 2 "Shall we go somewhere for a cup of coffee after class?" Tom said. 3 John said to Mary, "Why don't you wear your hair a little longer ?" 4 "Would you like another cup of tea?" the landlady said to the guest. 5 My sister said to me, "What about going to see Aunt Mary on Sunday?" 6 She asked me, "Have you ever seen a flying saucer?" 7 James said: "Do you want me to type this letter for you?" 8 Alfred said to John, "I didn't use your cassette player! Someone else did, not me." 9 Father said, "I was the superintendent while this school was being built."   10 The woman said, "If I had a gas stove, it would save me a lot of time."

Cách làm:

1. Chuyển câu hỏi trực tiếp thành câu hỏi gián tiếp:
- Tom asked the girl when she had had that picture taken.

2. Chuyển câu hỏi trực tiếp thành câu hỏi gián tiếp:
- Tom suggested going somewhere for a cup of coffee after class.

3. Chuyển câu hỏi trực tiếp thành câu hỏi gián tiếp:
- John asked Mary why she didn't wear her hair a little longer.

4. Chuyển câu hỏi trực tiếp thành câu hỏi gián tiếp:
- The landlady asked the guest if he would like another cup of tea.

5. Chuyển câu hỏi trực tiếp thành câu hỏi gián tiếp:
- My sister suggested going to see Aunt Mary on Sunday.

6. Chuyển câu hỏi trực tiếp thành câu hỏi gián tiếp:
- She asked me if I had ever seen a flying saucer.

7. Chuyển câu hỏi trực tiếp thành câu hỏi gián tiếp:
- James offered to type the letter for me.

8. Chuyển câu hỏi trực tiếp thành câu hỏi gián tiếp:
- Alfred denied using John's cassette player and claimed that someone else did.

9. Chuyển câu hỏi trực tiếp thành câu hỏi gián tiếp:
- Father mentioned that he was the superintendent while the school was being built.

10. Chuyển câu hỏi trực tiếp thành câu hỏi gián tiếp:
- The woman commented that if she had a gas stove, it would save her a lot of time.

Câu trả lời:
Tom asked the girl when she had had that picture taken.
Tom suggested going somewhere for a cup of coffee after class.
John asked Mary why she didn't wear her hair a little longer.
The landlady asked the guest if he would like another cup of tea.
My sister suggested going to see Aunt Mary on Sunday.
She asked me if I had ever seen a flying saucer.
James offered to type the letter for me.
Alfred denied using John's cassette player and claimed that someone else did.
Father mentioned that he was the superintendent while the school was being built.
The woman commented that if she had a gas stove, it would save her a lot of time.

John asked Mary why she didn't wear her hair a little longer.

Tom suggested going somewhere for a cup of coffee after class.

The girl asked Tom when he had the picture taken.

Để tính công thoát electron khỏi kim loại, ta sử dụng công thức Einstein: E = h*f - Φ, trong đó E là năng lượng của photon, h là hằng số Planck, f là tần số của photon và Φ là công thoát electron.

Với giới hạn quang điện λ 0 = 0.3 μm = 3.10^-7 m, ta tính được tần số f = c/λ0 = 3.10^8 m/s / 3.10^-7 m = 10^15 Hz.

Hằng số Planck h = 6.63 * 10^-34 J.s

Ta tính được công thoát electron: Φ = h * f = 6.63 * 10^-34 J.s * 10^15 Hz = 6.63 * 10^-19 J

Vậy câu trả lời cho câu hỏi trên là: B. 6,625 * 10^-19 J.