Progress so fon time.

（题文）In history, the Romanies were divided into different groups and developed their own languages, _____ there are now around sixty varieties.

I hope, first of all, that we shall never lose _____ heart in face of _____ failure

many times, my elderly mother still can’tremember how to light the gas.

____ about the man wearing sunglasses during night that he was determined to follow him．