收购要约期限不得小于三十日，并不得超过六十日。

Farming in the USA today is very different from that 100 years ago. In those days, farmers did not have many machines（机器） to help them. They had animals. 小题1:   __ This meant that farms were smaller than they are now. Farmers also worked in a different way in the past. In those clays, farmers grew fruits and vegetables and kept cows, pigs and chickens to feed their families. 小题2:   __ 

Farmers have a very special life in many ways. First of all, they can't leave the job at the end of the day. They live on the farm and there is always work to do. Second, a lot of farm work is outdoors, so the weather is very important for farmers. 小题3:    __  A lot of bad weather means farmers will lose money. Finally, farmers work with plants and animals. They understand nature better than other people do .

小题4:   __ Spring is a time for planting. Farmers are busy getting the fields ready and then: Planting the seeds(种子). In summer, farmers must take good care of the plants. Some may need water. Other plants may have problems with insects or diseases（疾病）. Then in fall, the fruits or plants are ready for picking. 小题5:   __  Winter is a time for rest or for work on the farm machines.

把A---E五个选项填入文中空缺处，使短文完整正确。

下列哪项不属于奇恒之腑（）

A.脉

B.女子胞

C.三焦

D.胆

E.脑

1931年11月27日，中华苏维埃共和国临时中央政府在（）成立

A、瑞金

B、兴国

C、于都

D、延安

多台推土机共同在一个工地作业时，推土机之间应保持的安全距离是多少？

脑出血最常见的动脉是（）

A.小脑齿状核动脉

B.基底动脉旁正中动脉

C.大脑中动脉豆纹动脉

D.脉络膜前动脉

E.前交通动脉