A：碳酸
B：汽油
C：蔗糖
D：合成纤维
将下列句子改为被动语态(1)I sent a letter to you last month.____(2) Do we use it for cooking?____(3) Where did you build the bridge?____(4) Mother tells me a story every day.____(5) Can he finish his homework on time?____
如图是某草原生态系统中的食物网．根据图回答：
When Jason failed to pay his bill，the network company ________his Internet connection.
