When first ______ to the market, these new products in their company enjoyed a great success.
| A．Introducing | B．introduced | C．to introduce | D．being introduced |
The boy likes playing jokes on his classmates, __________ of course makes him popular.
| A．which | B．whom | C．for which | D．for whom |
It is difficult, so I suggest that you __ it to an expert.
| A．should leave | B．will leave | C．are leaving | D．may leave |
Luckily, we’d brought a road map, _________ we would have lost our way.
| A．without it | B．with that | C．without which | D．without that |
The houses . They will be finished next year.
| A．are built | B．have been built | C．are being built | D．were built |
My throat is always by bad weather.
| A．affecting | B．effected | C．effect | D．affected |