5-21. grow, grows, to grow, growing, grew, grown.

[X is growing.] = X is becoming more big.

[Most living things grow for some time.]

5-22. heavy.

[X is heavy.] = X is difficult to lift. X is more difficult to lift than other things that are the same shape.

[I will need three people to lift this heavy container.]

5-23. length, lengths, length of, lengths of.

[The length of J is the same as the length of K.] = You know this about J and you know the same thing about K: You know J is not more long than K, and K is not more long than J.

[The length of the container cannot be less than the length of the thing inside.]

At one time, this animal was small, but then it grew.

Now the animal __________.

• is less heavy than before
• is the parent of this machine
• is the same length as this machine