He is extremely suspicious of all his neighbours.

他对所有邻居都满腹狐疑。

《新英汉大辞典》

He was not only surprised but, to start with, extremely suspicious.

他不但惊讶而且首先是十分怀疑。

youdao

Schools are extremely suspicious and really have little confidence in Ofqual's ability to regulate.

BBC: Heads challenge Ofqual to publish all GCSE grade research

"All of these illegal firearm purchases occurred under extremely suspicious circumstances, " according to the lawsuit.

CNN: Lawsuit seeks $75 billion in death of U.S. agent in Mexico

The developing countries are extremely suspicious that any new rules in these areas might be abused to discriminate against their products.

BBC: Key trade talks in the balance