—What do you think of Thomas?—Well, he is good, warm-hearted, hard-working and intelligent; _______, I can’t speak too highly of him.
---Why do you look so upset? ---There are so many troublesome problems _____.
The cancer risks ___________ smoking have been well documented.
They are purely __________ weapons, not designed for attacks.
It's not by any means a brilliant salary but it's ________for our needs.
There are strict limits on ____________ the country because a lot of social problem could arises and the country can’t take in a lot of new blind comers. .