Is this _____ eraser? [ ]
A. a
B. an
C. the
D. /
答案：B
It is very kind _____ you to help me with my work because it is very difficult _____me to do it by myself.
A．of； for
B．of； of
C．for；of
D．for； for
苗圃越冬保苗的方法有（）。
A、土埋
B、覆草
C、设防风障
D、架暖棚
E、灌水
