Trùng hợp hoàn toàn 16,8 gam etilen thu được polietilen. Số mắt xích $ -C{{H}_{2}}-C{{H}_{2}}- $ có trong lượng PE trên là
A.$ 4,{{140.10}^{22}}.$
B.$ 3,{{614.10}^{23}}.$
C.$ 12,{{460.10}^{23}}.$
D.$ 3,{{720.10}^{23}}.$

Khối lượng phân tử của tơ capron là 15000 đvC. Số mắt xích trung bình trong phân tử của loại tơ này gần nhất là:
A.118
B.133
C.113
D.145

Polime được trùng hợp từ etilen. Hỏi 280 gam polietilen đã được trùng hợp từ tối thiểu bao nhiêu phân tử etilen?
A.$ 3,{{01.10}^{24}} $
B.$ {{10}^{23}} $
C.$ 6,{{02.10}^{23}} $
D.$ 6,{{02.10}^{24}} $

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
My sister won her ………………… to Harvard for her activities outside her school.
A.fee
B.scholarship
C.grant
D.tuition

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Technology has its ………., like separating people and allowing hackers to steal information.
A.strengths
B.advantages
C.pros
D.drawbacks

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
………. are professionals who save people by performing operations.
A.surgeons
B.housewives
C.nurses
D.carers

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Many _____ organizations exist to help disadvantaged people for free.
A.non-government
B.non-profit
C.non-use
D.non-money

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Smartphones are great but they also ………. a lot of risks.
A.risk
B.entail
C.do
D.capture

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Our ………. is where people meet every Sunday to listen to the priest preaching.
A.grave
B.church
C.playground
D.garage

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
The ………. is in charge of many campaigns against corruption.
A.street
B.human
C.corruptible
D.government