If the machine makes a mistake -- ____ rarely happens -- it gives a warning in the form of a red light.
| A．that | B．which | C．as | D．what |
Today, _______ people speak English as their first, second or a foreign language than ever before.
| A．many | B．some | C．more | D．most |
It was the first time in two years that I________ my youngest son face to face.
| A．have seen | B．had seen | C．saw | D．see |
Greenland is _______ huge island that is mostly covered with_______ thick ice sheet.
| A．the; / | B．a; the | C．a; a | D．the; a |
Jack always sleeps late on Sundays. I’m sure he ______when we get home.
| A．is still sleeping | B．is to be sleep | C．will still be sleeping | D．will be about to sleep |
Since mid July, many areas in Shaanxi continuous heavy rain, leading to frequent natural disasters.
| A．saw | B．had seen | C．has seen | D．have seen |