使用拐杖的步行训练中，“患者先将双拐同时向前方伸出，然后支撑身体重心前移，使双足离地，下肢同时摆动，将双足摆至双拐落地点的邻近着地”属于（）

A.三点步

B.两点步

C.四点步

D.摆至步

E.摆过步

A warm thought suddenly came to me ______ I might use the pocket money to buy some flowers

for my mother's birthday. [ ]

A. if

B. when

C. that

D. which