水痘的主要传播途径是()
A.直接接触与呼吸道传播
B.性接触传播
C.粪-口传播
D.虫媒传播
E.动物源性接触传播
参考答案:A
. At the age of 29, Dave was a worker, ________ in a small apartment near Boston and ________ what to do about his future.
A.living; wondering
B.lived; wondering
C.lived; wondered
D.living; wondered
七年级七班教室后墙上的“学习园地”是一个长方形,其中一边长为3a,另一边长为2a-3b+1,则这个“学习园地”的面积为______.