It gives his life a flying start ______ he has gone abroad for further education.
_____it is 7 o’clock, we must go now.
The question is _____easy, so everyone in our class can answer it.
Our lab is on the third _____ of a six—______ building.
The flowers ____ sweet in the garden in spring.
-----when has the country been open to international trade? -----1978, I suppose.