ld scientist took up walking as a regular form of exercise, which, of course, is of great to his heath.

More highways have been built in China, _____ it much easier for people to travel from one place to another.[ ]

The science Festival is an occasion _____ modelplanes and model rockets are flown over the school grounds

_______ you ______to the United States —–No , never , but I went to Canada a few years ago.

Can you climb up the tall tree over there,David –Yes, let me _______.