1. There ______ also three flexible legs under the egg softening the impact on landing.
2. Proper devices of this kind ______ not been constructed yet.

4. The most useful of the materials which ______ available was also the cheapest.

5. That is the reason why the structures ________ down to the ground at a very high speed.
3. There ______ 5 categories for describing the final condition of the egg.


Select the appropriate verb to agree with the subject of the clause by dragging the correct alternative on the right to the gap in each sentence. When you have completed all 5 sentences, press the "Check answers " button.