从A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
( ) 1. — Alice, I can’t find my bike.
— Don’t worry. I saw ______ black one under the tree. Is it yours?
A. a B. an C. the D. 不填
( ) 2. It’s very convenient ______ us to buy train tickets now because we can buy them either from the station or on the Internet.
A. to B. of C. by D. for
( ) 3. ----Why did you vote for Maggie?
----Because she is very ________. She always shares things with others.
A. generous B. active C. practical D. energetic
( ) 4. — I have ______ in learning chemistry. Could you help me with it?
— Sure, I’d love to.
A. success B. interest C. trouble D. fun
