—What was your brother doing at this time yesterday?

—He was reading a magazine ________ I was writing an e-mail at home. [ ]

A. as soon as

B. after

C. until

D. while

水溶性薄膜衣料是（）。

A.卵磷脂

B.单硬脂酸丙二酯

C.黄原胶

D.聚山梨酯60

E.聚乙二醇