Cloning humans has been _____ in the science world for many years and it is likely to continue .
I don’t believe that he will marry Kathy whom he doesn’t love at all,________?
Rather than ________ on a crowded bus,he always prefers ________ a bicycle.
I think teachers should be strict _______ their students ______ studies.
The flat rent is expensive, I’ve got about half the space I had at home but I am paying ________ here.
—Do you have enough to _____all your daily expenses? ----Oh yes , enough and spare.