Multiple choice

Directions: Fill in the numbered blank (i) with the best option from those given.

Directions: Fill in the numbered blank with the best option from those given.

Radium is a radioactive element. Let us see what “radioactive” _____ (i) ____. Radioactive elements do not change from year to year. But a few of the heaviest atoms break down and change into other kinds. This breakdown or ____ (ii) _____ is called “radio activity”. Each radioactive element _____ (iii) ____ by giving off rays at a certain rate. This rate cannot be _____ (iv) ____ or slowed down by any known method. Some changes occur rapidly, others slowly, but in all cases the action cannot be _____ (v) ______ by man.

  1. explains

  2. gives

  3. means

  4. answers
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The sentence asks what "radioactive" means. "Means" is the correct verb to explain the definition of a term. "Explains" would need the term as subject (radioactivity explains), "gives" doesn't fit semantically, and "answers" would require the term to answer something, which is the opposite of what's happening here.

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