随着工业的高速发展,橡胶的产量和性能已不能满足工业生产的需要。近年来,人们合成了一种无机耐火橡胶,它的结构简式可能是
The children loved their day trip, and they enjoyed the horse ride ______.
Progress______ so far very good and we are sure that the work will be finished on time.
Charles was alone at home, with_______ looking after him.
It is often ______ that human beings are naturally equipped to speak.
I can’t leave. She told me that I ______ stay here until she comes back.