Revision for the mid-second term test-grade 11 (N03)

microbes" in paragraph 3 could best be replaced by which of the following?
A. Pieces of dust
B. Tiny bubbles
C. Tiny organisms D. Rays of light
Question 7: Lake Vostok is potentially important to scientists because ____. 
A. can be studied using radio waves
B. may contain uncontaminated microbes
C. may have elevated levels of ultraviolet light
D. has already been contaminated
Question 8: The purpose of the passage is to ____. 
A. explain how Lake Vostok was discovered
B. provide satellite data concerning Antarctica
C. discuss future plans for Lake Vostok
D. present an unexpected aspect of Antarctica's geography