Mark took off his coat and proceeded to undo his boots.（ ）
举一反三
- He took off his coat _______ he felt hot.
- He took off his coat _____________ he felt hot. A: because of B: as to C: if D: since
- 中国大学MOOC: _______ a girl had fallen into the river, he took off his coat and jumped into the water.
- What makes the man take off his hat and coat?
- He is taking off his coat. （改为一般疑问句）_____ _____ ______ ______ ______ coat?