What did the writer think of his experience of learning to play chess?
A、It helped him remain calm.
B、It helped him train his brain.
C、It made him proud of himsel
D、It made him question himself
3.In each of the following groups of words, there are four underlined letters or letter combinations marked A, B, C and D. Compare the underlined parts and identify the one that is different from the others in pronunciation.
A、useless
B、endless
C、unless
D、hopeless
We generally have four people working in the shop, but at ____ periods we employ extra hands.