At last, we found ourselves at the foot of a hill with trees providing shade and ________ down to eat our picnic lunch.
| A．sitting | B．having sat |
| C．to sit | D．sat |
The difficulty lies in ________ they will come to our help immediately.
| A．whether | B．that | C．if | D．which |
It is recently reported that quite a number of applications ________ from Apple’s official APP. Store are not safe to use.
| A．downloading | B．downloaded |
| C．having downloaded | D．to be downloaded |
Pointing to a small village at the foot of the mountain, he told us that was ________ he was born and brought up.
| A．what | B．in which | C．how | D．where |
The discovery was made in the 1950s, while the ________ of it was not recognized until half a century later.
| A．sacrifice | B．difference |
| C．significance | D．insurance |
Many of us would agree that improving the countryside through technology has great potentials ______ food development in China.
| A．in terms of | B．regardless of |
| C．in spite of | D．on account of |