Question

lie flat on your back and____ your knees bend
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Answer 1

Answer:

lie flat on your back and_on_your knees bend

Answer 2

Lie flat on your back and keep your knees bent.

• The answer to the blank will be "keep".
• The sentence is giving a command or an order to someone to lie flat on the ground and to keep the knees bent.
• The form of the verb "bend" will also be changed to 'bent'.
• The opposite of bend is to straighten up.