Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

Not until a monkey is several years old _________ to exhibit signs of independence from its mother.

A. beginning

B. does it begin

C. and begin

D. it begins

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

Not until a monkey is several years old _______ to exhibit sign of independence from its mother.

A. it begins

B. does it begin

C. and begin

D. is it begin

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

Mary is sixteen years old. She is _____ young to get married.

A. too

B. so

C. such

D. enough

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.

Not until now __________ popularly recognized that man is destroying the environment.

A. has it become

B. does it become 

C. it has become

D. it becomes

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

Not until late 1960s ___________ on the moon

A. that Americans walked

B. did Americans walk 

C. when did Americans walk

D. when Americans walked