商品是用于交换的劳动产品。下列属于商品的是
①原始森林 ②自产自用的蔬菜 ③商店里卖的衣服 ④送给同学的生日礼物 ⑤中国政府向地震灾区提供的紧急救援物资 ⑥家庭用的电、自来水；
| A．①②③ | B．④⑤⑥ | C．③⑥ | D．③④⑤ |
He has some problems _________ his English learning.
| A．on | B．for | C．with | D．in |
---What’re you _____?---My husband’s health problem _____ me a lot.
| A．worrying,worries |
| B．worried about,worries |
| C．worried about,worries about |
| D．worrying about,is worried about |
I usually do my homework _____than Mary. But she makes fewer mistakes because she is_____.
| A．more quickly; more careful | B．more quickly; more carefully |
| C．much quicker; more careful | D．much quicker; more carefully |
— People can print (打印) a 3-D camera now.
— How amazing! It looks like a ______one.
| A．true | B．real | C．truly | D．really |
Andy is really ______honest boy.He plays ______chess just for fun.
| A．an; the | B．an; / | C．a; / | D．a; the |