是hard to do sth 还是 hard doing sth
是hard to do sth 还是 hard doing sth
是hard for sb donging sth还是hard for sb to do sth
have a hard time 后接to do sth 还是doing 也是急用
it is hard to+Ving还是to do sth
是work hard at sth.还是work hard on sth.
use sth doing sth还是use sth to do sth
plan+to do sth.还是doing sth.还是 do sth.
expect to do sth还是doing sth?
mind doing sth还是 to do sth
learn+to do sth 还是 doing sth
finish to do sth还是doing sth
promise doing sth还是to do sth