Scientists are convinced ______ the positive effect of laughter ______ physical and mental health.
| A．of；at | B．by；in | C．of；on | D．on；at |
They stood _____ at each other as if they were enemies.
| A．staring | B．glancing | C．glaring | D．looking |
He risked _____ his job to see me off.
| A．losing | B．to lose | C．being lost | D．lost |
She finally got a high mark in writing. Never in all her life ____ so happy!
| A．did she feel | B．she felt | C．she had felt | D．had she felt |
I thought her nice and honest ______ I met her.
| A．first time | B．for the first time | C．the first time | D．by the first time |
--- You should have thanked her before you left.
--- I meant ______, but when I was leaving, I couldn’t find her anywhere.
| A．to do | B．to | C．doing | D．doing so |