Hailey’s comet becomes visible after every_________?
A. 86 years
B. 76 years
C. 1000 years
D. 365 years
A. 86 years
C. 1000 years
D. 365 years
A. Earth
B. Mercury
C. Jupiter
A. Plants
C. Animals
D. Bacteria
There are _____ kinds of joints present in a human body?
A. ozone accumulation
C. acid rain
D. allergens