题目

词汇 ，根据句意及汉语提示完成句子（每空一词）。 1. Last night, we stayed in a small __________(洞穴). 2. It isn’t __________(明智的) of Mary to go sightseeing in such bad weather. 3. I think Tony will get into __________(麻烦) for handing in his report late. 4. This book offers us good advice on how to solve problems of __________(日常的) life. 5. The Whites are going to attend a(n) __________(葬礼) this afternoon.每种进行有性生殖的生物的染色体数量能保持相对恒定，这是由于生物具有（   ）　　 A.有丝分裂和减数分裂   　     　        B.有丝分裂和受精作用 C.减数分裂和受精作用     　  　　       D.减数分裂和无丝分裂