Robust means strong and healthy.
what things are robust?
1.
2.
3.
4.

1. Robust frame

2. A robust strong coffee

3. A robust winning race horse

4. Robust, masonry work

answer; (d) i believe the best answer is ; ///people said that man could not fly, but in 1903, orville and wilbur wright made the first sustained powered flight in a heavier- than-air machine;