Jack wasn’t saying anything，but the teacher smiled at him ________he had done something very clever．
| A．as if | B．in case |
| C．while | D．though |
Little Jim sat under the tree, ___ about that maths problem.
| A．to think | B．and thinks | C．thought | D．thinking |
More than 70 percent of the playground in our school __ covered by water now.
| A．are | B．is | C．were | D．be |
Shanghai is __ the east of Nanjing.
| A．in | B．to | C．from | D．om |
The Great Wall took _ a new look after the People\s Republic of China was founded.
| A．for | B．on | C．in | D．at |
Tom is not used to __ in public.
| A．speak | B．speaking | C．being spoken | D．having spoken |