Food safety is important.Rules________ to protect people from food pollution.

A. took    B. is taken    C. has taken    D. was taken

A. will build    B. will be built

C. is built    D. builds

A. could    B. can

C. will    D. might

A. does    B. did    C. has done    D. will do

                          Organizing your household garbage

Dear foreign friends, glad to meet you here. Today I'd like to introduce new garbage sorting rules to you. In Shanghai, we are supposed to 1. the garbage into four groups, namely recyclable, harmful, dry and wet waste.  Paper, plastic, glass, and fabrics is 2. waste while food leftovers, plants, expired food is wet waste. Batteries, light tubes and 3. should be considered to be harmful waste. All other non-recyclable solid waste is called dry waste. We all believe that garbage sorting is 4. for the protection of the environment. Right? If people fail to sort their garbage, they will be fined up to 200 yuan. If all of us take pains to sort garbage, we'll lead a better life. So, let’s start right now.

Give the foreign students a piece of advice about garbage sorting.

5.

A．5：1     B．4：1     C．2：1     D．1：1

A．2.4%     B．3.2%     C．13.6%     D．6.8%

A．带火星的木条﹣﹣空气和氧气

B．观察颜色﹣﹣酒精和水

C．澄清石灰水﹣﹣二氧化碳和氮气

D．肥皂水﹣﹣软水和硬水

A．集气瓶中单位体积内氧分子个数多

B．集气瓶中石蜡与氧分子碰撞机会较多

C．空气中氧气浓度不如集气瓶内氧气浓度大

D．石蜡在空气中散发热量速度较快

A．都属于氧化物    B．都含有氧气    C．都含有氧分子    D．都含有氧元素