Scientists are convinced the positive effect of laughter_____physical and mental health.
| A．of, at | B．by, in | C．of, on | D．on, at |
______ sweet, this type of flower sells the best in the market.
| A．Smelt | B．Being smelt | C．To smell | D．Smelling |
The most widely accepted theory about the beginning of drama is based on the concept ______ drama evolved from ritual.
| A．which | B．that | C．when | D．as |
The growing speed of a plant is influenced by a number of factors, ______ are beyond our control.
| A．most of them | B．most of what | C．most of which | D．most of that |
______ Chief Engineer, as his family had expected, made his father happy and proud.
| A．Mike being appointed | B．Mike’s appointed |
| C．Mike appointing | D．Mike’s being appointed |
Storm chasing is so dangerous that some chasers are often hurt in accidents ______ by driving in a heavy rain.
| A．having caused | B．caused | C．to be caused | D．causing |