Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.
_______to Jim myself, I can’t really tell you why he would say such terrible things.
A.Not to have spoken
B.Not to be speaking
C.Because of not speaking
D.Not having spoken

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.
Littering doesn’t only make a place look ugly, but it also puts public health at risk and can _______ wildlife.
A.dangerous
B.danger
C.endangered
D.endanger

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.
We always unite and work together whenever serious problems ________.
A.devise
B.encounter
C.approach
D.arise

Why are bitcoins of great concern to governments?
A.Because most of bitcoin owners are hackers.
B.Because bitcoins may be used in illegal transactions.
C.Because the value of bitcoins is fluctuating wildly.
D.Because bitcoins will eventually replace national currencies.

What is the passage mainly about?
A.The future of bitcoins in the real world
B.A new kind of currency in the virtual world
C.A way of doing business in the virtual world
D.An alternative to bitcoins created by Nakamoto

Which of the following is defined in the passage?
A.Transactions
B.Public Databases
C.Credit cards
D.Bitcoins

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

A.educate
B.transfer
C.ancient
D.stranger

A.emotional
B.continuous
C.mandatory
D.adjustable

(23) ________
A.excluding
B.involving
C.having
D.including

(25) ________
A.offer
B.present
C.supply
D.provide