So far we have done a lot to build a low-carbon economy, but it is __________ ideal.We have to work still harder[ ]

The workers are so _____ to the noise of the machine that they don’t even notice it during their work. [ ]

A student in my class said to me, “if I ______ourmath teacher, I_____ make math learning easier and more interesting instead ofgiving the kids much homework to do every day.”

I’ll ask the teacher about the attributive clause I’m very puzzled about it— That’s just ________ most of our classmates have doubt[ ]

“It’s a secret…” he lowered his voice and whisperedno one could overhear it